You may remember the New York City explosion that killed eight and injured 50 people in Harlem. An investigation into the incident, which happened about 18 months ago, revealed that the explosion was caused by a leaking sewer pipe and an improperly welded join in a gas pipe.
The sewer link caused the earth under the gas pipe to subside. The gas pipe began to bend because the earth that had previously supported it was gone. The bend was at the site of a join with bad welding that ultimately cracked, releasing natural gas into the surrounding earth and utilities.
The investigation conducted by the National Transportation Safety Board showed that the pipe would not have cracked if the welding had been correctly performed. The failed weld was caused by using alcohol rather than the correct solvent to clean the pipe before welding it.
The investigation also revealed that the welder who last worked on the pipe had expired credentials. Another problem was the Con Ed dispatcher who notified the fire department but told them not to responded until further notice. Furthermore, no one called in the gas smell when it first appeared the night before the explosion. The call came the next morning, and the explosion happened 30 minutes later.
Another recent gas explosion caused extensive damage to a Bronx school, John F. Kennedy High School. The explosion last week seriously injured three construction workers at the school who were hospitalized with serious burns. This was the third major gas explosion during Mayor Bill de Blasio’s term.
Consolidated Edison is responsible for gas lines up to the meter; the building owner is responsible for lines inside a building.
The investigation into the Harlem disaster showed that the New York City as well as Con Ed and its subcontractors were responsible for the gas leak that caused the explosion. The city has begun an investigation into the explosion at the Bronx school.