ANDOVER, Massachusetts (REUTERS) - Some 8,000 people in Boston's suburbs had little hope of returning home soon as investigators scrambled on Friday (Sept 14) to find out the cause of dozens of gas explosions that destroyed scores of homes in the biggest such accident in nearly a decade.
The blasts on Thursday killed one person and left more than a dozen injured in Andover, North Andover and Lawrence - North of Boston - and left more than 18,000 homes and businesses without power, according to emergency officials.
Massachusetts State Police said around 70 fires, explosions or investigations of gas odor had been reported Thursday, though by Friday afternoon officials said that all had been extinguished. It was unclear how many of the fires and explosions were in homes or other locations.
It was the largest natural gas pipeline accident, in terms of the number of buildings involved, in the United States since 2010, when an interstate natural gas transmission line operated by Pacific Gas and Electric Company ruptured in San Bruno, California, destroying 38 buildings, damaging 70 more, and killing eight people, according to a Reuters analysis of incident reports from the National Transportation and Safety Bureau (NTSB).
Investigators suspected that over-pressurisation of a gas main belonging to Columbia Gas of Massachusetts led to the series of explosions and fires, Andover Fire Chief Michael Mansfield said on Thursday.
Frank Lupa, a 79-year-old retiree in Lawrence, spent the night in a middle school along with other dislodged residents, and said he prayed as chaos descended on his neighbourhood.
Lupa is unlikely to return home soon. Those driven from their homes "should expect that the restoration process will take several days or longer," Andrew Maylor, the town manager of North Andover, said on Twitter.
"This has been obviously an incredibly difficult day," Massachusetts Governor Charlie Baker said in a news conference early on Friday.
The Massachusetts natural gas distribution system is one of the oldest in the United States, with the age of some of the piping more than a century old, according to utility company disclosures with the Massachusetts Department of Public Utilities.
National Transportation Safety Board Chairman Robert Sumwalt said it would likely take investigators some time to examine the pipeline's design, maintenance and upgrades.
"The truth of the matter is we really don't have any factual information at this point to confirm," Sumwalt said on Friday.
Columbia Gas, a unit of utility NiSource Inc, is investigating, NISource spokesman Ken Stammen said on Thursday. Before the explosions, Columbia Gas had said it would be upgrading gas lines in neighborhoods across the state, including the affected suburbs.
NiSource shares fell more than 9 per cent on Friday morning.
"Our thoughts and continued support are with those who have been injured and affected. We are focused on providing as much support as possible to our customers, residents and communities," the utility said in a statement.
Fire and utility crews were still going door-to-door on Friday to conduct safety checks and shut off gas meters, officials said, after firefighters raced for hours from one blaze to another and utility crews rushed to shut off gas and electricity on Thursday.
Eighteen-year-old Leonel Rondon died when his car was crushed by a falling chimney, a spokeswoman for the Essex County District Attorney's office said. Lawrence General Hospital said it had treated 13 people for injuries ranging from smoke inhalation to blast trauma.
Guilia Holland, a 35-year-old mechanic in a wheelchair, said she had just gotten off a bus returning home when she saw "a big flash of light" at the house where she had been renting a room for a month.
"Good thing I wasn't home or I wouldn't be talking about it," she said outside an elementary school in Lawrence that the Red Cross had converted into a shelter for about 170 people.
South Lawrence Mayor Daniel Rivera urged residents to stay away from their homes.
"There could be still a gas leak in your home," Rivera said."You can't see it and in some cases you won't be able to smell it, and God forbid you go to sleep and don't wake up."
The US Department of Transportation's Pipeline and Hazardous Materials Safety Administration said it was sending a team to support the state's emergency response efforts.
"At this time, the focus remains on ensuring the public safety," Baker said. "Once that's complete, we will work with federal government and others to investigate how this occurred and hold the appropriate parties accountable for their actions."
In the past 20 years, about 100 people have died and 400 more have been hurt in major natural gas pipeline accidents investigated by the NTSB. Those accidents have caused more than US$100 million in damage.