After a series of gas explosions rocked through Merrimack Valley, Rep. Niki Tsongas says an ongoing federal investigation will show where Columbia Gas Company, the unit in charge of the network, may have dropped the ball.

“Unfortunately it takes these kinds of incidents and tragic accidents … that forces us all to take a harder look at the regulatory framework for our utilities,” Tsongas said during an interview with Boston Public Radio Monday. “There was a failure to communicate to residents who really had no idea what had happened and what the company was doing in response to it, so that just compounded a situation that in an of itself was certainly terrifying.”

Tsongas represents Massachusetts’ third district, which includes Lawrence, one of the three towns hit by the incident. Andover and North Andover were also hit, but their schools have gone back into session while Lawrence has yet to send students back to class.

“Progress is underway, but it was slow to come and there is much work to be done,” Tsongas said.

In a press conference Friday, Lawrence Mayor Dan Rivera criticized Columbia Gas for their lack of communication regarding the cause of the explosions and the lack of communication with customers throughout the crisis. “I’ll be damned,” Rivera said Friday, “if we are going to wait another six hours for them to get off their ass.”

Shortly after, Gov. Charlie Baker declared a state of emergency and brought in Eversource to oversee the rehabilitation.

Tsongas said she spoke with one of the vice presidents of Columbia Gas, a conversation that did not bolster her faith in the company.

“My takeaway really was that they really had no plan in place, either how to communicate as I mentioned with the customers or the communities, and were not forthcoming about their way forward and what they were doing,” she said. “‘I think just out of deep concern for public safety, the governor did have to declare a state of emergency and bring in Eversource to oversee it. I think, as a result, we’re seeing the kind of progress that we absolutely have to have.”

According to Tsongas, an exact timeline for restoring gas service is still unknown, but it should take “quite a while” to repair every home and neighborhood. “It’s going to create a lot of discomfort for many people who won’t be able to have a hot shower for a good number, awhile, we’re not quite sure how long that’s going to be, or use any gas appliances, so a lot of inconvenience still to come,” Tsongas said.

Pressure sensors were connected a gas line that was taken out of service shortly before the blasts, according to an ongoing investigation by the National Transportation Safety Board, the federal entity tasked with looking into the cause.

“The [National Transportation Safety Board] is in town and starting to assess what, exactly, happened, but we’re yet to get to the why it happened,” Tsongas said. “They’ve stated overpressurization, but it’s not clear exactly why there was overpressurization ... that’s all part of the investigation yet to come.”

To hear Rep. Tsongas’ full interview with Boston Public Radio, click on the audio player above.