Increased pressure reported in Massachusetts pipeline, according to NTSB

More than 60 suspected gas fires broke out Thursday night in homes in the cities of Lawrence, Andover and North Andover, in North Boston. One person was killed, several were injured and dozens of people were evacuated. About 18,000 customers lost energy, reported National Grid.

"We are very interested in understanding Columbia Gas's operations, reviewing their record keeping, compliance with procedures, procedures, training, oversight of their subcontractors," Sumwalt said on Saturday.

Sumwalt also noted that there are 14 gas pressure regulators in the area and that investigators plan to test them all and make sure that they all work properly. He expects NTSB investigators to stay on site for seven to ten days while they collect perishable evidence and conduct interviews.

"Our mission is to discover what has happened so that we can prevent it from recurring," Sumwalt said.

Sumwalt said that they would work to determine the cause of the incident and publish a preliminary report, but that a full detailed report on the exact cause might not be complete until two years later.

There is no evidence at this time that anything bad has contributed to the fires, said Sumwalt.

State of emergency

The gas lines were closed in the three cities. Hundreds of natural gas technicians were expected to come down to the cities in the coming days to restore the gas service safely before electricity is turned on, state officials said.

It is not known when people who evacuated their homes will be allowed to return. Sumwalt said the Massachusetts Utilities Department and the gas companies would make that decision, not the NTSB.

Jeff Hall, spokesman for the Red Cross, said Friday there were nearly 400 shelters after the explosions and fires on Thursday night.

"Evacuations are by the thousands," Hall said Friday, adding that he expected many residents to stay with friends and family in the area.

Eversource tweeted Saturday that it was working to close more than 8,000 gas meters, and the company said it anticipated "this crucial first phase would be almost complete" on Saturday night.

On Friday, the governor said Colombia was "simply insufficiently prepared" to effectively manage relief efforts.

Mayor Daniel Rivera of Lawrence, one of the affected towns, said about the company: "It just seemed like there was no one in charge, like they were in the weeds , and they've never seen it before. "

The chairman of the public utility, Steve Bryant, then defended the company's performance, saying the company had remained in constant contact with state and federal authorities.

"I would say we have progressed as quickly as possible," he told reporters. "I do not think anyone could have handled that would have gone further than us right now."

Bryant expressed his condolences to the victim's family, apologized for the inconvenience to the clients, and said the company was providing "all the resources possible to repair the damage."

"It looked like Armageddon"

Thursday night, houses exploded in the three cities, destroyed by more than 60 fires of gas.

"It looked like Armageddon, it really did," said Michael B. Mansfield, Chief Fire Rescue Officer of Andover.

As pressure mounted for gas companies to provide answers on what had happened, Sens. Ed Markey and Elizabeth Warren of Massachusetts have called for congressional hearings on explosions and fires.

Public service works with officials to "investigate this incident"

Columbia Gas Transmission was owned by NiSource until 2015, when the company became Columbia Pipeline Group. Later, this company was integrated with TransCanada.

According to its website, NiSource is one of the largest natural gas distributors in the United States serving more than 3.4 million customers in seven states. The company also provides distribution, production and transmission services to nearly 500,000 customers in northern Indiana.