LAWRENCE, MA (WFSB) - A teenager is dead and several other people were hurt after a series of explosions and fires just north of Boston.
Friday morning, the National Transportation Safety Board said it launched an investigation to try and determine the cause of the explosions.
"Our job is to determine what happened and make sure it doesn't happen again," said Robert Sumwalt, NTSB chairman.
Thousands of homes in three communities were evacuated on Thursday night.
Authorities said there were nearly 40 fires. At one point, 18 simultaneously burned.
"I was in the backyard and just heard a massive explosion," said Paul Mancaniello, a neighbor.
Entire neighborhoods were evacuated in Lawrence, Andover and North Andover on Thursday.
Many of the homes involved customers serviced by the Columbia Gas company.
"There were somewhere between 60 and 80 structure fires across the three communities," said Chief Michael Mansfield, Andover, MA Fire Department. "There were three explosions as well."
In Lawrence, MA, an 18-year-old was killed after a chimney toppled onto a car. The Essex District Attorney's Office identified him as Leonel Rondon.
Many other people were hurt.
Crews said they worked to depressurize the gas lines. By late Thursday, all of the fires were doused.
Power companies had to cut electricity to prevent further fires.
Many areas were silent and dark overnight.
People were grateful for the out of state crews trying to help them get their lives back in order.
Crews for Norwich Public Utilities entered houses on Friday in Lawrence, MA to check that the gas meter was off, then verified with a gas sensor that there was no elevated gas level in the homes.
"Right now the focus is every house," said Mayor Dan Rivera, Lawrence, MA. "Go in there, shut the gas off, make it safe so people can go back in their house as soon as possible."
Many families were home and had to evacuate until all gas and electric service was shut down to eliminate any more danger of house fires caused by what the mayor says was higher than normal pressure in the gas lines.
"It just seems like there is no one in charge. Like they are in the weeds and have never seen this before," said Rivera.
The FBI is investigating the explosions, along with state police and local authorities.
Gov. Charlie Baker said it could take days or weeks before a cause is discovered.
Schools in all three communities were canceled on Friday. Some of them were used as shelters for residents.
The chairman of the NTSB said while they normally investigate incidents, like crashes, this falls under their jurisdiction because gas pipelines transport gas from one place to another.
The chairman stressed that the agency will not be responsible for determining when it's safe for residents to return home.
As part of response efforts, Columbia Gas crews need to visit each of the 8,600 affected customers to shut off each gas meter and conduct a safety inspection.