Lawrence General Hospital says it's treating six patients from the gas explosions including two in critical condition.
Columbia Gas President Steve Bryant later defended the company's performance, saying the utility had remained in constant touch with state and federal officials.
The Massachusetts Emergency Management Agency said it appeared the gas lines had become over-pressurised.
Officials said dozens of fires and explosions were reported after an apparent gas line problem.
Before evacuating from North Andover, Jeremy Melvin described a chaotic scene near the plumbing shop where he works.
A house at 85 Colonial Road in Lawrence was actively smoking as firefighters hosed it down just after 5 p.m. Minutes later, Nam said he heard a loud boom from his neighbour's house and the ground shook. Three people rushed out.
By 7:00pm local time, officials in Andover said all fires in the town had been extinguished. The cities are north of Boston. Video showed roofs and walls consumed by flames that billowed thick black smoke.
State police now puts the tally of fires and explosions at 70, up from the 39 initially reported, with the number expected to grow. In a release dated Thursday the company had said it would "be upgrading natural gas lines in neighbourhoods across the state".
He warned anyone with concerns to leave their houses and head to North Andover High School, which is being set up as a gathering point. Columbia Gas of MA, the NiSource unit responsible for the local network, said in a statement that its crews would need to visit each of the 8,600 affected customers to shut off each gas meter and carry out a safety inspection. It said it was conducting safety checks and supporting first responders.
Residents in North Andover who were evacuated were told to "expect that the restoration process will take several days - or longer", by the town manager, Andrew Maylor. About 18,000 customers were without power.
An 18-year-old man died when a chimney toppled by an explosion fell on his vehicle in the city of Lawrence, according to the North Andover newspaper, The Eagle-Tribune.
Razin said he arrived just as residents were being evacuated, and immediately saw the house two doors down was leveled from an explosion. Passengers on three were being moved by bus.
The Andover Senior Center and Andover Youth Center have been open for residents who have been displaced.
"Numerous evacuations of neighbourhoods where there are gas odours are underway", police said.
As many families seek refuge in temporary shelters, officials are warning that it could be at least another day until many of them are allowed to return to their homes.
In Andover a robocall was made to residents asking them to shut off the gas in their homes, but people on social media were asking how to do so and expressing confusion.
Soon after the fire, Andover police sent out an alarm urging residents to evecuate their homes and turn their gas pipes off. Lawrence Mayor Dan Rivera said that all the residents have been asked to evacuate their homes.
Gas service was interrupted for 250 customers in Lawrence last month "due to hit line by a third party", according to Columbia Gas.
The US Department of Transportation's Pipeline and Hazardous Materials Safety Administration said it was sending a team to support the state's emergency response efforts.