# Natural Gas-Fueled Building Explosion and Resulting Fire - **operation:** document - **citation:** DCA14MP002 - **title:** Natural Gas-Fueled Building Explosion and Resulting Fire - **source type:** incident - **agency:** National Transportation Safety Board - **status:** current - **official:** true - **published on:** 2020-11-13 - **effective on:** 2014-03-12 - **summary:** Pipeline occurrence. in Manhattan, NY, USA. on 2014-03-12 - **machine formats:** - **json:** https://regulus.evalyn.ai/document/ntsb-case-dca14mp002.json - **markdown:** https://regulus.evalyn.ai/document/ntsb-case-dca14mp002.md - **app url:** https://regulus.evalyn.ai/document/ntsb-case-dca14mp002 - **source url:** https://www.ntsb.gov/investigations/Pages/DCA14MP002.aspx **body:** NTSB investigation DCA14MP002. Event Date: 2014-03-12 Event City: Manhattan Event State Or Region: NY Event Country: USA Completion Status: Completed Probable cause: The National Transportation Safety Board determines that the probable cause of the accident was (1) the failure of the defective fusion joint at the service tee, installed by Consolidated Edison Company of New York, Inc., in 2011, that allowed natural gas to leak from the gas main and migrate into the building where it ignited and (2) a breach in the sewer line that went unrepaired by the New York City Department of Environmental Protection since at least 2006 that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the gas main, which caused the line to sag and overstressed the defective fusion joint. Tier1Name: Unknown Tier2Name: Pipe structural malfunction/failure Tier1Name: System operating Tier2Name: Pipe structural malfunction/failure Tier1Name: System not operating Tier2Name: Pipe structural malfunction/failure Tier1Name: Initiating product flow Tier2Name: Servicing event Tier1Name: System operating Tier2Name: Inspection event Tier1Name: System shutdown Tier2Name: Emergency shutoff Tier1Name: Post-release Tier2Name: Evacuation Tier1Name: Post-release Tier2Name: Emergency response Tier1Name: System operating, changing flow/pressure Tier2Name: Fire/explosion (post-release) Tier1Name: System maintenance Tier2Name: System disabled Tier1Name: System operating Tier2Name: Miscellaneous/other Finding Tier1Name: Organizational Finding Tier2Name: Management Finding Tier3Name: Communication (organizational) Finding Modifier Name: Pipeline operator Finding Report Text: Organizational - Management - Communication (organizational) - Pipeline operator Finding Tier1Name: Organizational Finding Tier2Name: Support/oversight/monitoring Finding Tier3Name: Oversight Finding Modifier Name: State/Local agency Finding Report Text: Organizational - Support/oversight/monitoring - Oversight - State/Local agency Finding Tier1Name: Pipeline Finding Tier2Name: Pipeline structure Finding Tier3Name: Joint/weld/seam Finding Modifier Name: Failure Finding Report Text: Pipeline - Pipeline structure - Joint/weld/seam - Failure Finding Tier1Name: Pipeline Finding Tier2Name: Pipeline structure Finding Tier3Name: Joint/weld/seam Finding Modifier Name: Design Finding Report Text: Pipeline - Pipeline structure - Joint/weld/seam - Design Finding Tier1Name: Personnel Finding Tier2Name: Experience/knowledge Finding Tier3Name: Skill/ability Finding Modifier Name: Pipeline maintenance personnel Finding Report Text: Personnel - Experience/knowledge - Skill/ability - Pipeline maintenance personnel Finding Tier1Name: Personnel Finding Tier2Name: Action/decision Finding Tier3Name: Information processing/decision making Finding Modifier Name: Pipeline maintenance personnel Finding Report Text: Personnel - Action/decision - Information processing/decision making - Pipeline maintenance personnel Finding Tier1Name: Pipeline Finding Tier2Name: Pipeline handling/service Finding Tier3Name: Securing Finding Modifier Name: Unintentional use/operation Finding Report Text: Pipeline - Pipeline handling/service - Securing - Unintentional use/operation Finding Tier1Name: Pipeline Finding Tier2Name: Pipeline operation/capability Finding Tier3Name: Pipeline integrity/capacity Finding Modifier Name: Design Finding Report Text: Pipeline - Pipeline operation/capability - Pipeline integrity/capacity - Design Finding Tier1Name: Environment/Infrastructure Finding Tier2Name: Conditions/weather/phenomena Finding Tier3Name: Precipitation Finding Modifier Name: Use of related info Finding Report Text: Environment/Infrastructure - Conditions/weather/phenomena - Precipitation - Use of related info Finding Tier1Name: Environment/Infrastructure Finding Tier2Name: Conditions/weather/phenomena Finding Tier3Name: Precipitation Finding Modifier Name: Unknown/Not determined Finding Report Text: Environment/Infrastructure - Conditions/weather/phenomena - Precipitation - Unknown/Not determined Finding Tier1Name: Environment/Infrastructure Finding Tier2Name: Task environment Finding Tier3Name: Pressures/demands Finding Modifier Name: Awareness of condition Finding Report Text: Environment/Infrastructure - Task environment - Pressures/demands - Awareness of condition Finding Tier1Name: Personnel Finding Tier2Name: Action/decision Finding Tier3Name: Action Finding Modifier Name: Other government personnel Finding Report Text: Personnel - Action/decision - Action - Other government personnel Finding Tier1Name: Environment/Infrastructure Finding Tier2Name: Conditions/weather/phenomena Finding Tier3Name: Precipitation Finding Modifier Name: Awareness of condition Finding Report Text: Environment/Infrastructure - Conditions/weather/phenomena - Precipitation - Awareness of condition Finding Tier1Name: Environment/Infrastructure Finding Tier2Name: Conditions/weather/phenomena Finding Tier3Name: Precipitation Finding Modifier Name: Contributed to outcome Finding Report Text: Environment/Infrastructure - Conditions/weather/phenomena - Precipitation - Contributed to outcome Official NTSB investigation data. NTSB findings determine probable cause and make safety recommendations; they do not adjudicate civil liability or regulatory violations. What Happened On March 12, 2014, about 9:30 a.m. eastern daylight time, two adjacent multiuse five story buildings were destroyed by a natural gas fueled explosion and resulti ng fire. The buildings were situated on the west side of Park Avenue between East 116th Street and East 117th Street in the East Harlem district of the Borough of Manhattan in New York City. The violent explosion damaged buildings on the east and west side s of Park Avenue and along East 116th and East 117th Streets. The Metro North R ailroad suspended rail service for about 7 1/2 hours on the elevated railway along Park Avenue because of debris from the explosion on the track. Eight people died, more than 50 people were injured, and more than 100 families were displaced from their homes as a result of this accident. The cost to Consolidated Edison Company of New York, Inc. (Con Edison), of equipment damages, emergency response activities, remediation, and replacement exceeded $1.9 million. What We Found We determined that the probable cause of the accident was (1) the failure of the defective fusion joint at the service tee, installed by Consolidated Edison Company of New York, Inc., in 2011, that allowed natural gas to leak from the gas main and migrate into the building where it ignited and (2) a breach in the sewer line that went unrepaired by the New York City Department of Environmental Protection since at least 2006 that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the gas main, which caused the line to sag and overstressed the defective fusion joint. What We Recommended As a result of this investigation, We made the following new safety recommendations: To the City of New York: Implement a written program or procedure to ensure the integrity of your sewer lines, repair breaches in a timely manner, and coordinate with other agencies to identify and address potential soil disruption and voids. (P-15-33) To Consolidated Edison Company of New York, Inc.: Revise your plastic pipe fusion welding procedure to require cleaning of the surfaces to be welded with suitable solvents to remove all dirt, water, oil, paint, and other contaminants as recommended in ASTM F2620, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings. (P-15-34) Revise your plastic pipe fusion welding procedure to specify that the solidified beads should be visually examined after completing a joint to ensure the beads are uniformly shaped and sized around the joint as recommended in ASTM F2620, Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings. (P-15-35) Provide clear written guidance to the Gas Emergency Response Center staff on the conditions for promptly notifying the New York City Fire Department and provide additional staff training. (P-15-36) Extend your gas main isolation valve installation program to include strategic locations where long distribution mains currently cannot be isolated, giving priority to pipelines in more densely populated areas. (P-15-37) To the New York State Public Service Commission: Revise the New York State Department of Public Service gas utility operator program to ensure all elements of the regulations are included in the 5-year audit plan. (P-15-38) PAR-15-01 <<>> Natural Gas-Fueled Building Explosion and Resulting Fire New York City, New York March 12, 2014 Accident Report NTSB/PAR-15/01 PB2015-104889 National Transportation Safety Board <<>> NTSB/PAR-15/01 PB2015-104889 Notation 8696 Adopted June 9, 2015 Pipeline Accident Report Natural Gas-Fueled Building Explosion and Resulting Fire National Transportation Safety Board 490 L’Enfant Plaza, S.W. Washington, D.C. 20594 <<>> National Transportation Safety Board. 2015. Natural Gas-Fueled Building Explosion and Resulting Fire. Pipeline Accident Report NTSB/PAR-15/01. Washington, DC. Abstract: On March 12, 2014, about 9:30 a.m. eastern daylight time, two adjacent multiuse five-story buildings were destroyed by a natural gas-fueled explosion and resulting fire. The buildings were situated on the west side of Park Avenue between East 116th Street and East 117th Street in the East Harlem district of the Borough of Manhattan in New York City. The violent explosion damaged buildings on the east and west sides of Park Avenue and along East 116th and East 117th Streets. Eight people died, more than 50 people were injured, and more than 100 families were displaced from their homes as a result of this accident. The accident investigation focused on the following safety issues: the adequacy of Consolidated Edison’s (Con Edison) quality assurance and quality control procedures for joining plastic pipes, the effectiveness of Con Edison’s public awareness program, the adequacy of Con Edison’s gas odor report response, the effectiveness of the New York City Department of Environmental Protection sewer integrity program, and the effectiveness of federal and state oversight. Safety recommendations are made to the New York State Public Service Commission, the City of New York, and Con Edison. The National Transportation Safety Board (NTSB) is an independent federal agency dedicated to promoting aviation, railroad, highway, marine, and pipeline safety. Established in 1967, the agency is mandated by Congress through the Independent Safety Board Act of 1974 to investigate transportation accidents, determine the probable causes of the accidents, issue safety recommendations, study transportation safety issues, and evaluate the safety effectiveness of government agencies involved in transportation. The NTSB makes public its actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and statistical reviews. The NTSB does not assign fault or blame for an accident or incident; rather, as specified by NTSB regulation, “accident/incident investigations are fact-finding proceedings with no formal issues and no adverse parties … and are not conducted for the purpose of determining the rights or liabilities of any person.” 49 C.F.R. § 831.4. Assignment of fault or legal liability is not relevant to the NTSB’s statutory mission to improve transportation safety by investigating accidents and incidents and issuing safety recommendations. In addition, statutory language prohibits the admission into evidence or use of any part of an NTSB report related to an accident in a civil action for damages resulting from a matter mentioned in the report. 49 U.S.C. § 1154(b). For more detailed background information on this report, visit http://www.ntsb.gov/investigations/dms.html and search for NTSB accident ID DCA14MP002. Recent publications are available in their entirety on the Internet at http://www.ntsb.gov. Other information about available publications also may be obtained from the website or by contacting: National Transportation Safety Board Records Management Division, CIO-40 490 L’Enfant Plaza, SW Washington, DC 20594 (800) 877-6799 or (202) 314-6551 NTSB publications may be purchased from the National Technical Information Service. To purchase this publication, order product number PB2015-104889 from: National Technical Information Service 5301 Shawnee Rd. Alexandria, VA 22312 (800) 553-6847 or (703) 605-6000 http://www.ntis.gov/ <<>> NTSB Pipeline Accident Report Contents Figures ........................................................................................................................................... iii Table ................................................................................................................................................v Acronyms and Abbreviations ..................................................................................................... vi Executive Summary .................................................................................................................... vii 1 Factual Information ....................................................................................................................1 1.1 Accident Synopsis ......................................................................................................................1 1.2 Accident Site ..............................................................................................................................2 1.3 Gas Odor Calls to Con Edison ...................................................................................................2 1.4 Emergency Response .................................................................................................................4 1.5 Injuries .......................................................................................................................................5 1.6 Damages .....................................................................................................................................5 1.7 Natural Gas and Other Utilities..................................................................................................6 1.8 Preaccident Activities ................................................................................................................8 1.8.1 Gas Odor Reports ............................................................................................................8 1.8.2 Gas Leak Surveys ..........................................................................................................10 1.8.3 Water Leak Surveys .......................................................................................................10 1.8.4 Sewer Inspections ..........................................................................................................10 1.8.5 Street Cave-ins and Repairs ...........................................................................................11 1.9 Con Edison Operations ............................................................................................................12 1.9.1 Heat Fusion Procedure ...................................................................................................12 1.9.2 Emergency Call Response .............................................................................................13 1.9.3 Pipeline Integrity Management ......................................................................................14 1.9.4 Emergency Preparedness and Response ........................................................................14 1.10 Tests and Research .................................................................................................................15 1.10.1 Materials Laboratory Examination of Accident Pipe and Joint ...................................15 1.10.2 Saddle Fusion Joints ....................................................................................................17 1.10.3 Accident Service Tee ...................................................................................................19 1.10.4 Accident Saddle Joint Fusion Bead Size .....................................................................21 1.10.5 Gas Pipe Size and Dimensional Conformity ...............................................................22 1.10.6 Mechanical and Physical Properties ............................................................................22 1.10.7 Finite Element Modeling .............................................................................................23 1.10.8 Metallurgical Examination of Cast Iron Water Pipe ...................................................23 1.11 Public Awareness ...................................................................................................................25 1.11.1 Regulatory Requirements ............................................................................................25 1.11.2 Con Edison Public Awareness Program ......................................................................26 1.11.3 Con Edison Public Awareness Program Leak Recognition and Response .................27 1.11.4 Con Edison Public Awareness Program Effectiveness ...............................................27 i <<>> NTSB Pipeline Accident Report 1.12 Regulatory Oversight .............................................................................................................28 1.12.1 Federal Oversight .........................................................................................................28 1.12.2 New York State Oversight ...........................................................................................29 1.12.3 Comparison of Federal and State Regulations .............................................................30 1.13 Postaccident Activities ...........................................................................................................32 1.13.1 FDNY Fire Investigation .............................................................................................32 1.13.2 Con Edison Heat Fusion Procedure Upgrade ..............................................................32 1.13.3 Sewer Inspection and Excavation ................................................................................32 1.13.4 Gas Pressure Tests .......................................................................................................33 1.13.5 Examination of Area Below the Pavement ..................................................................33 1.13.6 New York City Underground Infrastructure Working Group .....................................36 1.13.7 Use of 911 for Gas Odor Calls ....................................................................................37 1.13.8 Plastic Fusion Welder Qualifications ..........................................................................38 1.13.9 New York Public Service Commission Notice of Proposed Rulemaking ...................40 2 Analysis ......................................................................................................................................41 2.1 Water Main Damage ................................................................................................................41 2.2 Sewer Damage .........................................................................................................................41 2.3 Gas Main and Service Tee .......................................................................................................42 2.3.1 Service Tee Failure Examination ...................................................................................42 2.3.2 Fusion Joint Operator Qualification ..............................................................................44 2.4 Con Edison Emergency Call Response ....................................................................................45 2.5 Con Edison Public Awareness Program ..................................................................................46 2.6 Alignment of State and Federal Gas Pipeline Regulations ......................................................46 3 Conclusions ................................................................................................................................48 3.1 Findings....................................................................................................................................48 3.2 Probable Cause.........................................................................................................................49 4 Recommendations .....................................................................................................................50 Appendix A. Investigation ...........................................................................................................52 Appendix B. Timeline ..................................................................................................................53 References .....................................................................................................................................55 ii <<>> NTSB Pipeline Accident Report Figures Figure 1. Buildings on west side of Park Avenue between East 116th and East 117th Streets before March 12, 2014, accident. ...................................................................... 1 Figure 2. Buildings 1644 and 1646 Park Avenue in New York City after March 12, 2014, explosion.............................................................................................................. 6 Figure 3. Overhead view of accident block. .................................................................................. 7 Figure 4. Gas main, water main, and sewer main positions below road at gas service tee location. ......................................................................................................................... 8 Figure 5. Sewer damage on south-facing video frame from October 2006 inspection. .............. 11 Figure 6. Exemplar gas main with service tee welded to it ........................................................ 13 Figure 7. Saddle fusion machine................... .............................................................................. 13 Figure 8. Exemplar service tee showing cutter and seal cap. ...................................................... 15 Figure 9. Accident 8-inch-diameter HDPE service main (top) and HDPE service tee at left of 2-inch-diameter HDPE service pipe (bottom). ............................................................... 16 Figure 10. Installed configuration of accident 2-inch-diameter service pipe and 8-inch-diameter main. ................................................................................................................... 16 Figure 11. Exemplar saddle fusion joint service tee assembly with a round base portion and showing three distinct fusion beads. .......................................................................... 17 Figure 12. Inlet face of exemplar service tee that was pressed against heater adapter plate (heating iron) preheated to about 500°F but not fusion joined to a pipe. ................ 18 Figure 13. Fracture faces after drop weight tests on exemplar service tee inlet fusion joint from the sound fusion joint (left) and the oil-contaminated fusion joint (right). ................. 19 Figure 14. Upper fracture face (saddle end) recovered from accident saddle fusion joint ......... 20 Figure 15. Fusion joint on 8-inch gas main recovered from accident site. .................................. 20 Figure 16. Exemplar saddle fusion joint service tee assembly with a round base portion showing three distinct fusion beads. ............................................................................................. 22 Figure 17. Mating fracture faces of 12-inch cast iron water main. .............................................. 24 iii <<>> NTSB Pipeline Accident Report Figure 18. North water main pipe segment fracture face showing regions of graphitic corrosion that appear as dark features adjacent to outer and inner surfaces. ................................ 25 Figure 19. Schematic comparing federal and New York regulatory definitions of service line leading to a gas meter inside a building. ................................................................... 31 Figure 20. Water containing fluorescent dye flowing into sewer main through damaged area in east side of sewer main as shown in a video frame from March 28, 2014, inspection. .... 33 Figure 21. Circumferential crack in exposed 12-inch cast iron water main near 8-inch HDPE gas main. ............................................................................................................................ 34 Figure 22. Eight-inch HDPE gas main, detached service tee, and service line in front of Building 1642 with closeup of detached service tee. .................................................. 35 Figure 23. Voids and gaps in ground beneath sidewalk in front of Buildings 1642 and 1644. Inset photo shows void above brick basement foundation at Building 1644. .............. 36 iv <<>> NTSB Pipeline Accident Report Table Table 1. Injuries. ..............................................................................................................................5 v <<>> NTSB Pipeline Accident Report Acronyms and Abbreviations API American Petroleum Institute ASTM ASTM International Buildings 1642, 1644, 1646 1642, 1644, and 1646 Park Avenue Call Center Con Edison Customer Service Call Center CFR Code of Federal Regulations Con Edison Consolidated Edison Company of New York, Inc. CSR customer service representative DOT US Department of Transportation FDNY New York City Fire Department FDS Manhattan Fire Dispatch System GERC Gas Emergency Response Center HDPE high-density polyethylene mechanic gas distribution service mechanic Metro-North Metro-North Railroad NGA Northeast Gas Association NTSB National Transportation Safety Board NYCDEP New York City Department of Environmental Protection NYCDOT New York City Department of Transportation NYCRR New York Codes, Rules and Regulations NYPD New York City Police Department NYPSC New York Public Service Commission NYSDPS New York State Department of Public Service OPS Office of Pipeline Safety PHMSA Pipeline and Hazardous Materials Safety Administration psig pounds per square inch, gauge vi <<>> NTSB Pipeline Accident Report Executive Summary On March 12, 2014, about 9:30 a.m. eastern daylight time, two adjacent multiuse five-story buildings were destroyed by a natural gas-fueled explosion and resulting fire. The buildings were situated on the west side of Park Avenue between East 116th Street and East 117th Street in the East Harlem district of the Borough of Manhattan in New York City. The violent explosion damaged buildings on the east and west sides of Park Avenue and along East 116th and East 117th Streets. The Metro-North Railroad suspended rail service for about 7 1/2 hours on the elevated railway along Park Avenue because of debris from the explosion on the track. Eight people died, more than 50 people were injured, and more than 100 families were displaced from their homes as a result of this accident. The cost to Consolidated Edison Company of New York, Inc. (Con Edison), of equipment damages, emergency response activities, remediation, and replacement exceeded $1.9 million. The National Transportation Safety Board determines that the probable cause of the accident was (1) the failure of the defective fusion joint at the service tee, installed by Consolidated Edison Company of New York, Inc., in 2011, that allowed natural gas to leak from the gas main and migrate into the building where it ignited and (2) a breach in the sewer line that went unrepaired by the New York City Department of Environmental Protection since at least 2006 that allowed groundwater and soil to flow into the sewer, resulting in a loss of support for the gas main, which caused the line to sag and overstressed the defective fusion joint. The accident investigation focused on the following safety issues:  Adequacy of Con Edison’s quality assurance and quality control procedures for joining plastic pipes. A Con Edison contractor installed the service tee in 2011 using a Con Edison heat fusion procedure for plastic pipe. Postaccident examination of the separated service tee joint showed fracture features indicating that the surfaces were contaminated, resulting in a weak joint. Review of the Con Edison plastic pipe fusion procedure revealed that some industry-standard steps, such as cleaning the surface with alcohol, were omitted. In addition, inspection of the fusion joint revealed inconsistent bead sizes.  Effectiveness of Con Edison’s public awareness program. Con Edison had an extensive public awareness program that included informing the public and gas customers to call Con Edison in the event of a suspected gas leak. This information was included in customer billings, in newspaper advertisements, and in flyers posted in apartment buildings. However, the investigation found that people who said they smelled gas the day before the accident did not call Con Edison, the fire department, or 911.  Adequacy of Con Edison’s gas odor report response. About 25 minutes before the accident, Con Edison received a call from a resident of an adjacent building who reported a gas odor inside and outside of his residence. He said the gas was coming from one of the accident buildings. During the call, the Con Edison customer service vii <<>> NTSB Pipeline Accident Report representative’s computer stopped responding, which delayed the notifications. Although a gas service mechanic was dispatched, the fire department was not notified as required by Con Edison’s response procedure.  Effectiveness of the New York City Department of Environmental Protection sewer integrity program. Investigators discovered a large breach in the sewer main near the destroyed buildings that had gone unrepaired for more than 8 years. They also learned of recurring major street repair work in the vicinity of the sewer breach over several years. This work included a repair that was made a few days before the accident to correct significant ground settling below the pavement in the vicinity of the gas main and building service lines.  Effectiveness of federal and state oversight. The state pipeline safety program certifications in Title 49 United States Code section 60105(a) allow states to inspect and enforce intrastate pipeline safety. The state must adopt the minimum federal regulations for pipeline safety. Examination of the New York state pipeline safety regulations revealed that they are less stringent than the federal regulations in two areas: definition of service line and pipeline pressure testing. These deficiencies were not identified by the Pipeline and Hazardous Materials Safety Administration during state program recertifications. As a result of this investigation, the National Transportation Safety Board makes safety recommendations to the New York State Public Service Commission, the City of New York, and Consolidated Edison Company of New York, Inc. viii <<>> NTSB Pipeline Accident Report 1 Factual Information 1.1 Accident Synopsis On March 12, 2014, about 9:30 a.m. eastern daylight time, two adjacent multiuse five-story buildings were destroyed by a natural gas-fueled explosion and resulting fire. The buildings were situated on the west side of Park Avenue between East 116th Street and East 117th Street in the East Harlem district of the Borough of Manhattan in New York City. (See figure 1.) Figure 1. Buildings on west side of Park Avenue between East 116th and East 117th Streets before March 12, 2014, accident. The violent explosion damaged buildings on the east and west sides of Park Avenue and along East 116th and East 117th Streets. The Metro-North Railroad (Metro-North) suspended rail service on March 12 for about 7 1/2 hours on the elevated railway along Park Avenue because of debris from the explosion on the track. Eight people died, more than 50 people were injured, and more than 100 families were displaced from their homes as a result of this accident. Although the amount of natural gas released from the distribution system could not be accurately estimated, Consolidated Edison Company of New York, Inc. (Con Edison) stated that in the worst-case scenario, at the operating pressure of 8 inches of water column (about 1/3 pound per square inch, gauge [psig]), up to 1 <<>> NTSB Pipeline Accident Report 158 cubic feet of natural gas could be released per minute through the 1 7/8-inch-diameter hole that was tapped into the 8-inch-diameter high-density polyethylene (HDPE) gas main in front of Building 1642. The cost of equipment damages, emergency response activities, remediation, and replacement to Con Edison exceeded $1.9 million. 1.2 Accident Site The building at 1644 Park Avenue (Building 1644) was a five-story walk-up built about 1898. It contained the Spanish Christian Church, which occupied the basement and the first two floors, and three residential floors with two apartments on each floor.1 This building had an oil-fired heating system, with natural gas used for cooking. Five fatalities occurred in this building. The building at 1646 Park Avenue (Building 1646) also was a five-story walk-up built about 1898. This building contained a piano store that occupied the basement and the first floor and four residential floors with two apartments on each floor; one of the eight apartments was vacant. Three fatalities occurred in this building. The building at 1642 Park Avenue (Building 1642) had four stories and four apartments and was built in 2011. It was significantly damaged in the explosion. 1.3 Gas Odor Calls to Con Edison About 9:06 a.m. on March 12, a resident of Building 1652 called the Con Edison Customer Service Call Center (Call Center) to report a natural gas odor.2 The caller’s building was north of and next to Building 1646. (See figure 1.) The caller reported smelling gas both inside and outside and said that the odor was coming from “another building … right next to [this one].” The caller further described the odor as coming from a building with a piano store. During the call, the Call Center computer system stopped responding to the customer service representative’s [CSR] entries), and the CSR put the call on hold several times. The call took about 6 minutes to complete. The CSR told the caller to evacuate immediately, and added, “we’ll be there within 45 minutes.” At 9:12 a.m., the CSR called the Con Edison Gas Emergency Response Center (GERC) and spoke with a dispatcher about the gas odor report. Con Edison’s Gas Operations Emergency Response Plan describes GERC in section 3.2. a. (4) (Con Edison 2014): The GERC is responsible for the safe and reliable operation of the company’s gas distribution system. Activities include dispatching and directing gas crews in response to gas odor reports and other gas system problems, and monitoring excavation activities in the vicinity of gas transmission mains and identifying/initiating contingency plans. The GERC coordinates emergency response efforts associated with incidents on the gas distribution system and 1 The New York City Fire Department (FDNY) determined that the explosion and fire originated inside of 1644 Park Avenue, in the Spanish Christian Church on the first and second floors, when a mixture of natural gas and air was ignited by an unidentified ignition source (FDNY 2014). 2 See appendix B for a timeline of the activities of Con Edison and first responders beginning with the call to Con Edison. 2 <<>> NTSB Pipeline Accident Report implements the incident command system. GERC is responsible for notifying and receiving information from appropriate federal, state, or local agencies, including first responders, regarding gas distribution system status. The GERC maintains the Emergency Contact and Notification list for Gas Operations and first responders. … The Con Edison computer system was designed so that data from the call taken by the CSR—time, location, content—was transmitted to the GERC computer system. In addition, the Con Edison procedure required the CSR to call GERC to confirm that the key information from the report was received and correctly understood as it had been entered into the computer. On March 12, when the CSR called GERC after receiving the gas odor call from Building 1652, she told the dispatcher that her computer was down, but then she noted that it was back up and said that she was entering a ticket for an indoor gas leak.3 The dispatcher asked the CSR to call back. About 9:13 a.m., the CSR made a second call to GERC to confirm receipt by the dispatcher of the indoor gas leak ticket that she had just entered and to confirm the key information provided by the caller. During this call, the CSR gave the address and details of the ticket to the dispatcher. The CSR indicated that the caller had stated that there was a smell of gas both inside and outside. The dispatcher told the CSR that another ticket, for a report of gas odor outside, should be entered into the computer. About 9:15 a.m. the dispatcher called a gas distribution service mechanic (mechanic) who was about 4 miles away from the location of the gas odor report. The dispatcher told the mechanic that he would receive two tickets for gas odor, one for inside the building and one for outside. About 9:16 a.m. the CSR made a third call to the GERC dispatcher to follow up the outside gas leak ticket. The CSR told the dispatcher that the computer system was “freezing” and asked if the ticket for Building 1652 had been received. The dispatcher said that it had not. About 9:19 a.m. the dispatcher called the New York City Fire Department (FDNY) to report the gas odor at Building 1652. During the call, the dispatcher said, “Hold up, no, sorry, hold on one second, hold on, hold on, I’ll call you right back.” After this call, GERC made no calls to the FDNY before the buildings exploded at 9:30 a.m. About 9:39 a.m. the GERC operations manager called the Manhattan Fire Dispatch System (FDS), which is part of the FDNY, to ask whether the FDNY had received any reports of fire at the Park Avenue location of the gas odor report. The FDNY operator said that there was a report of a “building that exploded” at Park Avenue and 114th Street, it had “collapsed, and it’s on fire.” About 9:46 a.m. the operations manager called all Manhattan gas operations personnel to request that all available personnel respond to the explosion location. 3 A ticket is a work order for a mechanic to investigate a gas odor report. 3 <<>> NTSB Pipeline Accident Report The GERC operations manager called a gas construction planner about 9:55 a.m. to discuss where to dig fire banks to stop the flow of natural gas to the two destroyed buildings.4 The operations manager told the planner that he would call back once he determined the distance from the curb line to the gas mains. About 10:08 a.m. he called the New York State Department of Public Service (NYSDPS) to report where the fire banks would be located. Fire bank excavation began in three locations about 10:45 a.m. By 1:44 p.m. Con Edison had completed the emergency excavations and the necessary p - **truncated:** true - **body characters:** 146796