Some 8,000 people were driven from their homes in the Boston suburbs by a series of gas explosions, and it was unclear on Friday when they could go back.
The blasts killed at least one person, injured 12 more and destroyed dozens of homes and other buildings in Andover, North Andover and Lawrence on Thursday.
Residents who were evacuated "should expect that the restoration process will take several days or longer," Andrew Maylor, the town manager of North Andover, said on Twitter.
Firefighters raced for hours from one blaze to another and utility crews rushed to shut off gas and electricity to prevent further explosions. Fire and utility crews were going door to door to conduct safety checks, officials said.
Some 70 fires, explosions or investigations of gas odor had been reported, Massachusetts State Police said.
"This has been obviously an incredibly difficult day," Massachusetts Governor Charlie Baker said in a news conference early on Friday.
An 18-year-old Lawrence man, Leonel Rondon, died when one explosion knocked over a chimney that fell on his car, a spokeswoman at Massachusetts General Hospital 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."
Fire investigators suspected "over-pressurization of a gas main" belonging to Columbia Gas of Massachusetts, a unit of the utility NiSource Inc, caused the explosions, Andover Fire Chief Michael Mansfield told a news conference.
Baker said that he told the utility company that it must bring in additional resources and develop a comprehensive safety plan for each of the communities.
"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." NiSource spokesman Ken Stammen said Columbia Gas was investigating. The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration said it was sending a team to support the state's emergency response efforts.
The former head of the agency, Brigham McCown, called the series of gas explosions "unprecedented, at least in recent memory."
The National Transportation Safety Board have a team of investigators headed to the area, officials said. The Federal Bureau of Investigation also was sending investigators, the Boston Globe reported.