NTSB Safety Recommendation Letter P-76-012

Page 1Official PDFSPORTAT lO D WASHINGTON, D.C. FOR RELEASE: 6:30 A,M,, E,s,T,, APRIL. 19, 1976 ( 2 0 2 ) 426-8787 ISSUED: April 19, 1976 Forwarded to: Honorable Carla A. H i l l s Secretary SAFETY RECOMMENDAT I O N ( S ) Department of Housing and Urban Development P-76-12 Washington, D. C. 20410 A t 6:57 a . m . on April 2 2 , 1974, a massive, low-order explosion demolished the w e s t w a l l of a 25-story commercial building a t 305 E a s t 45th Street i n New York, New York. The s t r u c t u r e of t h e adjacent building was damaged and g l a s s w a s broken i n other buildings i n the area. G l a s s fragments and s l i v e r s were blown i n t o 46th S t r e e t , where they l a y 1 inch deep i n places. N o persons were k i l l e d , but more than 70 persons were injured. The National Transportation Safety Board's investigation showed t h a t a 6-inch gas service l i n e located i n the basement of t h e building had been struck from below and severed by a ruptured hydropneumatic pressure tank i n s t a l l e d d i r e c t l y underneath. Gas a t 7 inches of water column flowed a t 54,000 cubic f e e t per hour from t h e open end of the separated service l i n e . G a s leakage continued f o r about 1/2 hour. Gas odors were noticed by a building occupant, but no gas detection equipment had been i n s t a l l e d and therefore no alarm w a s sounded. The occupant who smelled gas a l e r t e d the night watchman of the incident and i n i t i a t e d a telephone call t o report the matter. The building exploded before the escaping gas could be shut off and before t h e sources of i g n i t i o n could be eliminated. G a s vapor detection equipment is available and i n use for the detection of gas. The more reliable, higher q u a l i t y equipment is expensive, b u t work i s being done t o produce a dependable, moderately priced instrument. One system employs a c e n t r a l l y located detection u n i t with numerous detection heads which can be located i n various p a r t s of a building where gas might accumulate. 1745#

Page 2--- instruments located at strategic positions in their interior. These instruments are designed to activate sprinkler systems if the instr are triggered by the smoke or heat of a fire. It seems logic requlations could be adopted for the installation of gas detection instruments in buildings. Therefore, the National Transportation Safety Board reco Department of Housing and Urban Development: Investigate the practicability and the availability c vapor detection instruments for installation at strategic locations in buildings. Based on the results of this inves gation, recommend guidelines to appropriate State and loca government agencies for regulations for the installation o gas detection instruments in buildings. (Recommendation P-76-12)(Class 11, Priority Followup) TODD. Chairman, McADAMS, THAYER, BURGESS, arid HALEY, Members, COncurre By: THIS DOCUMENT WILL BE WLEASED TO THE PUBL IC DISSEMINATION OF THIS Dl JCUMENT#