(CNN) Massachusetts Gov. Charlie Baker declared a state of emergency Friday in three towns north of Boston rocked by a string of deadly gas explosions, and he put another utility company in charge of restoration efforts.

"Today, on a number of very significant issues, we heard one thing and something else happened," Baker told reporters.

Baker said Eversource would replace Columbia Gas of Massachusetts on the same day he warned stunned residents of the towns that the return to normalcy could take time following blasts Thursday that set homes ablaze, forced evacuations and left one person dead.

Later in the day, the governor said Columbia was "simply inadequately prepared" to effectively manage relief efforts.

Mayor Daniel Rivera of Lawrence, one of the affected towns, said of the company, "It just seemed like there's no one in charge, like they're in the weeds, and they've never seen this before."

Utility President Steve Bryant later defended the company's performance, saying the company had remained in constant touch with state and federal officials.

"I would say that we've advanced this as rapidly as it could possibly be advanced," he told reporters. "I don't think that anybody else managing this would've been further down the road than we are at the moment."

Bryant expressed his condolences to the victim's family, apologized for the inconvenience to customers and said the company was providing "all the resources that we possibly can to be able to correct the damage."

Hundreds of natural gas technicians were to descend on Lawrence, Andover and North Andover in the coming days to restore gas service safely before electricity could be turned on, state officials said.

"Utility technicians must do their jobs in order to make sure everyone has a safe place to return to," Baker said. "This will not be an easy process and we ask for continued patience."

Kurt Schwartz, director of the Massachusetts Emergency Management Agency, said, "How long is it going to take? As long as it takes. ... We don't know today how long this will take."

A house goes up in flames Thursday in northeastern Massachusetts north of Boston.

The investigation into the cause -- involving the National Transportation Safety Board and other federal agencies -- is in its early stages, officials said.

"Once the utilities secure the affected areas we'll work with the federal government to investigate how this occurred and who should be held accountable for the results and actions," Baker said.

As pressure mounted for gas company officials to provide answers about what happened, Sens. Ed Markey and Elizabeth Warren of Massachusetts called for a congressional hearings on the explosions and fires.

"People have a right to know," Markey told reporters. "There's oftentimes a tendency, when there are accidents like this, for a company to huddle down, to try to protect their shareholders when their one goal should be just to protect the people who they are serving. We're going to be here to make sure that that happens."

Thursday evening, homes erupted in flames across the three towns, consumed by more than 60 suspected gas fires.

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

One house in Lawrence exploded, sending the chimney flying. It crashed into a nearby car, fatally wounding a teenager who was inside. Leonel Rondon, 18, and two of his friends were in the car when the debris struck, his family told CNN affiliate WHDH . He later died at the hospital, authorities said.

Also in Lawrence, a boiler inside Ra Nam's house caught fire, he told CNN affiliate WCVB

Minutes later, he said he heard a loud booming sound from his neighbor's house. Three people rushed out. About 25 people, including two firefighters, were wounded, officials said.

"This has been an overwhelming event," Mansfield said. "I have been in the fire service for almost 39 years and I have never seen anything like this in my entire career."

Firefighters battle a house fire Thursday in North Andover, Massachusetts.

Gas, power shut off

Gas technicians and first responders went door to door reviewing thousands of homes in Lawrence, Andover and North Andover and shutting down gas mains.

Massachusetts State Police confirmed at least 70 responses to fire, explosions and gas odor reports.

The NTSB sent a team Friday to investigate what "appears to be multiple explosions involving (a) natural gas pipeline in the Merrimack Valley area of Massachusetts," Chairman Robert Sumwalt said.

Sumwalt said his agency would look at "the design of the pipeline system, any maintenance or upgrades being done or in process of being done on the pipeline. The integrity management system of the pipeline operator Columbia Gas. We'll look at the emergency response, the system safety program of the pipeline operator."

"Our mission is to find out what happened, so that we can learn from it and keep it from happening again," he said.

Thousands can't go home

Authorities cautioned it was "far too early to speculate" on the cause of the explosions.

Earlier Thursday, before the fires broke out, the utility company that services the area announced it would be upgrading natural gas lines in neighborhoods across the state.

"Weather permitting, work will take place Monday through Friday," Columbia Gas said in a statement. Andover, North Andover and Lawrence were included in the planned projects.

Gas service was interrupted for 250 customers in Lawrence last month because of a line hit by a third party, according to the company. It's unclear whether that incident was related to Thursday's fire and explosions.

Residents protect their faces against the smoke while being evacuated Thursday in Lawrence, Massachusetts.

The governor said he urged Columbia Gas to develop a "comprehensive safety inspection plan."

Utility works with officials to 'investigate this incident'

A house in Lawrence is reduced mostly to rubble Thursday after a series of explosions.

In a statement Friday, Columbia Gas said crew members are working to restore power with the help of other utility companies.

"Our thoughts are with the community and everyone impacted by yesterday's tragic incident. We are focused on providing as much support as possible to our customers, residents and communities," the company said in the statement

Columbia Gas also said it's working with officials to "investigate this incident in order to understand its cause."

This is not the first time that a subsidiary of NiSource, the parent company of Columbia Gas of Massachusetts, has been the subject of a federal probe stemming from a disaster.

A Columbia Gas Transmission Corporation natural gas pipeline burst in West Virginia in 2012 and NTSB investigators determined that external corrosion, which could have been discovered by the pipeline operator, was at fault.

Columbia Gas Transmission was owned by NiSource until 2015, when the company was spun off into Columbia Pipeline Group. Later, that company became part of TransCanada.

NiSource is one of the largest natural gas utilities in the United States, serving more than 3.4 million customers in seven states, according to its website. The company also provides electric distribution, generation and transmission services to almost 500,000 customers in northern Indiana as well.