A series of gas explosions has left at least four people injured and ignited fires in at least 39 homes in communities north of Boston, in the US state of Massachusetts.
Entire neighbourhoods were forced to evacuate as crews scrambled to fight the blazes and turn off gas and electricity lines to prevent further damage.
Massachusetts State Police urged all residents with homes serviced by Columbia Gas in Lawrence, Andover and North Andover to leave their properties on Thursday afternoon (local time).
A man whose neighbourhood was among dozens that erupted in fire said he ran into his basement to find the room was glowing.
Ra Nam, a Lawrence resident, said he was in his yard when the smoke detector in his basement went off about 4:30pm.
When he ran downstairs and saw the boiler on fire, he quickly grabbed a fire extinguisher and put it out.
Minutes later, Mr Nam said he heard a loud boom from his neighbour's house and the ground shook.
He said a woman and two kids had made it out of the house but the basement was on fire.'Total destruction'
Late on Thursday Lawrence resident Bruce Razin was among the evacuees standing outside the Colonial Heights neighbourhood near the city's high school trying to decide what to do next.
Officials had cut power in the area and the streets were pitch black, except for the lights coming from emergency vehicles.
Mr Razin said he arrived just as residents were being evacuated, and immediately saw the house two doors down was levelled from an explosion.
"I couldn't imagine if that was my house," he said.
Fires blamed on gas lines
"It's total destruction. I'd be completely devastated."
Lawrence General Hospital said it was treating four people with injuries related to the fires, but it did not provide details about their condition.
The Massachusetts Emergency Management Agency blamed the fires on gas lines that had become over-pressurised, but officials who responded to the area were still investigating the cause.
State officials said Columbia Gas was working to ease pressure on gas lines following the fires.
Columbia had announced earlier in the day it would be upgrading gas lines in neighbourhoods across Massachusetts, including the area where the explosions happened.
It was not clear whether work was happening there on Thursday, and a spokeswoman did not immediately return calls.Scenes of panic
Some local officials described scenes of panic as residents rushed to evacuate, many wondering if their homes would be next to erupt in flames.
In North Andover, town selectman Phil Decologero said his entire neighbourhood had gathered in the street, afraid to enter their homes.
Just a few streets down, he said, homes were burning.
"It's definitely a scary situation at the moment," he said. "It's pretty severe."
Aerial footage of the area showed some homes that appeared to be torn apart by blasts.
At one, the upper portion of a brick chimney had crushed a car parked in the driveway.
Schools and senior citizen centres have been opened as gathering points for residents who fled their homes.
Lawrence City Councillor Marc Laplante said "people need to get out … [but] it's really difficult because the traffic right now is horrendous".'You can't even see the sky'
In nearby Methuen, police chief Joseph Solomon said 20 to 25 homes were on fire in Lawrence when he responded to help.
He said there were so many fires "you can't even see the sky".
By 7:00pm local time, officials in Andover said all fires in the town had been extinguished.
Massachusetts State Police said electricity was being shut off for all residents in Lawrence, North Andover and Andover, where some were still reporting an odour linked to natural gas.
The three communities house more than 146,000 residents and are located about 42 kilometres north of Boston.