WASHINGTON, DC
Federal regulators on Tuesday found Consolidated Edison to be largely
responsible for the explosion of natural gas that destroyed two
apartment buildings in East Harlem last year and killed eight people.
The
National Transportation Safety Board, which investigates gas explosions, pipeline ruptures, plane crashes
and other disasters, decided that the primary cause of the blast on
March 12, 2014, was a faulty connection between two of Con Edison’s
plastic gas pipes under Park Avenue. The fusion of the two pipes failed,
allowing gas to escape into the ground and migrate into one of the
buildings, where it became concentrated enough to combust, the safety
board found.
The
safety board’s staff also concluded that rescue crews could have
arrived at the scene and begun evacuating the block about 15 minutes
before the 9:30 a.m. blast if the utility had alerted the New York Fire
Department right away. A neighborhood resident called the utility at
about 9:06 a.m., saying he smelled gas inside and outside his apartment
building, they said.
Con
Ed did call the Fire Department about 13 minutes later, but then
withdrew the call before the department sent any crews, the safety
board’s staff found. They quoted a Con Ed dispatcher on the phone with
the department, saying: “Hold up. No, sorry. Hold on. Hold on. I’ll call
you right back.”
Eleven
minutes later, the explosion rocked the entire block, damaging
buildings on both sides of Park Avenue, leaving more than 100 families
homeless and disrupting train service on the Metro-North Railroad tracks
above Park until late in the day.
The
safety board also faulted the city’s Department of Environmental
Protection for neglecting for at least eight years to repair a gaping
hole in a sewer main in front of the buildings that were destroyed in
the blast. Con Edison officials have pointed to the erosion caused by
that broken sewer main as a contributing factor in the explosion. City
officials have disputed that contention.
Just
days before the safety board took up the cause of the explosion in
Harlem, Con Edison filed suit against the city, blaming the city’s
failure to maintain the sewer and water mains near its gas pipes. In the
suit, filed in State Supreme Court in Manhattan, the company contended
that the city’s Transportation Department had repeatedly been notified
of depressions in the pavement of Park Avenue that indicated the earth
beneath the surface was eroding.
The utility is seeking to have the city shoulder the liability in lawsuits filed by victims of the explosion and their families.
The
hearing was the first public airing of the safety board’s findings from
an investigation that took more than a year. The board’s investigators
were at the scene within a day of the blast, collecting evidence and
interviewing witnesses.
The
safety board is best known for investigating crashes of planes, trains
and long-haul trucks. But it also oversees gas pipelines and,
technically speaking, Con Edison’s gas mains under the city’s streets
fit that bill. The heavy toll of the explosion in Harlem drew the safety
board’s attention.
The
main that ran under the block of Park Avenue where the blast occurred
was made of cast iron and had been installed more than 120 years ago.
Iron pipes of that vintage are prone to springing leaks, but documents
the safety board released this year indicated that the source of the
trouble may have been newer plastic pipes that had been connected to the
old main.
Con
Edison replaced a 69-foot section of the cast-iron main with plastic
pipe in 2011. The utility used a small plastic pipe to connect that new
section to a building at 1642 Park Avenue.
One
of the documents released said investigators had injected traceable gas
into the main to locate any leaks. They found high concentrations of
the gas had escaped into the ground in front of 1642 Park at a point
where the main was new plastic, not part of the old iron pipe, according
to the document. They also found that the smaller pipe, known as a
service line, had separated from the main. While 1642 Park survived the
explosion, two neighboring buildings — at 1644 and 1646 Park, near 116th
Street — were destroyed.
During
the investigation, the safety board determined that the foreman who
oversaw Con Edison’s installation of the plastic section of the main had
not kept his qualifications to do that work up-to-date. State
regulators later found that 70 percent of Con Edison’s pipe fitters had
not kept their qualifications current. The company said it would retrain
all of the workers who install and maintain its network of gas mains.