Five days after a series of explosions and fires rocked the Merrimack Valley, thousands are still waiting to go home, though not everyone has a home to go to.

“There really are going to be two groups here: People who are permanently displaced as a result of what happened on Thursday, and people for whom there’s just going to be a tremendous amount of inconvenience,” Governor Charlie Baker said on Monday.

Those who returned home after being forced to evacuate Thursday came back to buildings without gas. Forty-eight miles of gas pipeline has to be replaced, and Eversource, the company now in charge of the situation, estimates that it will likely take weeks for gas to be fully restored.

Baker says a new local relief fund managed by the Essex County Community Foundation will also help. The fund should be in place by the end of the week, he said.

"What we think we need to do is make sure that people who have needs, legitimate and critical needs, because of the disruption associated with this, get addressed,” Baker said.

“Part of what we are hoping that this particular fund will be able to do is provide people with options and ways to deal with the issues associated with what happens when its not 50 degrees out or 60 degrees out at night and during the day,” he said.

Columbia Gas spokesman Scott Ferson says they’ve processed 1,500 requests for immediate assistance and are providing gift cards for food and other needs. And he says they’re working on addressing long-term needs of the 8,500 affected households.

“They’re going to differ from household to household,” Ferson said. “Some have heat, some use [gas] for cooking and other things. So how do you address those individual needs?”

For cooking, he says, that may include providing something like electric stoves. With temperatures starting to drop, Ferson says the utility doesn't know how many households use natural gas for heat.

In the meantime, federal officials say the investigation into the explosions is partially focused on pressure-sensors connected to a gas line that was being taken out of service shortly before the blasts began.

Massachusetts Senators Ed Markey and Elizabeth Warren fired off a letter to Columbia Gas and NiSource, quoting federal regulators as saying the pressure inside Columbia Gas' pipes was 12 times higher than the system was intended to hold. They say they want 19 specific questions answered by Wednesday, including details on a management plan, readings in their Columbus Ohio Control room last week and their emergency response protocol.

“Of course we want to know why this could happen in the first place. I mean, people’s houses literally just started blowing up. That’s insane,” Rep. Seth Moulton told WGBH News. “That’s what you might expect if you go to sleep as a terrorist in Afghanistan. You understand your house might get blown up in the middle of the night. But not when you’re a good citizen of Massachusetts going to sleep in North Andover or Lawrence.”

Moulton said that it wasn't until 10:30 on Saturday night that he finally got a call-back from the CEO of Columbia Gas.

“He was very polite and whatnot, but it still sounds like they’re out to lunch, and just don’t really understand the magnitude of this crisis," Moulton said. “He didn’t even acknowledge that a young man lost his life, in the course of our conversation.”

That young man was 18-year-old Leonel Rondon. He died when a brick chimney fell on a car he was in. There were three other people who escaped from the vehicle unharmed.

People impacted by last week's natural gas fires and explosions in Lawrence, Andover and North Andover are beginning to talk with attorneys about filing class-action lawsuits against Columbia Gas.

Attorney Constantine Kyros says regulated utilities in Massachusetts are protected from lawsuits in ordinary cases like snowstorms and hurricanes, but not in cases of gross negligence. His firm is speaking to people who were impacted by the incident about filing a suit. Kyros points out some people are filing claims with the utility to be reimbursed for losses.

“Assuming that that isn't satisfactory or it doesn't cover the costs of the damages that these people have sustained, then there could be an avenue to pursue legal claims in the form of either a class or an individual basis,” Kyros explained.

Several other law offices are also asking potential clients to contact them about filing class-action suits.

Mary Blake and Matt Baskin contributed to this report.