At least one person has been killed and others injured after a series of suspected gas explosions rocked towns north of Boston in Massachusetts on Thursday evening.
Local police reported “fires and explosions” at dozens of properties.
Hundreds of people have been evacuated, with gas and electricity services cut to try and prevent further incidents.
A local fire chief described it as an “overwhelming event” that resembled “Armageddon”.
“I have been in the fire service for almost 39 years and I have never seen anything like this in my entire career,” Andover Fire Rescue Chief Michael Mansfield said.
Police said at least 39 fires were reported in homes and businesses in the towns of Lawrence, Andover and North Andover – located approximately 30 miles (45km) north of Boston.
Witness accounts suggest the incidents began at about 16:30 local time (20:30 GMT).
Mr Mansfield said investigators suspected the fires were caused by “over-pressurisation of a gas main” belonging to Columbia Gas lines, but this has not been confirmed.
The Governor of Massachusetts, Charlie Baker, said at a press conference on Thursday evening that the situation was “still very much an active scene”.
“There will be plenty of time later tonight, tomorrow morning and into the next day to do some of the work around determining exactly what happened and why,” he said.
The gas firm’s parent company Indiana-based NiSource said its thoughts were with those affected by the incident.
“The first priority for our crews at the scene is to ensure the safety of our customers and the community.”
What do we know about the victims?
Eighteen-year-old Leonel Rondon was killed inside a car in Lawrence when a chimney fell on his vehicle from a house explosion, a spokeswoman with the Essex County District Attorney’s office said.
Family members told local media that he had been in the car with two friends, who were now in hospital.
The total amount of people injured in the incidents is not yet clear, but Lawrence General Hospital is said to be treating at least 10 people for fire-related injuries.
At least two of those are reported to be in a serious condition.
What is the situation now?
Lawrence Mayor Dan Rivera asked all South Lawrence residents – even if they do not have Columbia Gas – to evacuate their homes amid a planned power shut down.
He described the community as “very resilient” but warned people they might not be able to return home immediately.
He also added that they had been contacted by the White House about the situation.
A number of evacuation centres were set up for residents at local schools, which officials said would remain closed on Friday.
Almost 18,000 customers were without power on Thursday evening because of the emergency switch-offs, according to the Massachusetts Emergency Management Agency.
State police tweeted that they had responded to 70 instances of fires, explosions or gas odours across Lawrence and Andover in total.
Neighbouring Police Chief Joseph Solomon, who came in to assist from the town of Methuen, said there were so many fires burning at one point that you couldn’t see the sky.
According to the Boston Globe newspaper, all fires were reportedly under control by 20:00 local time (00:00 GMT).
The State Fire Marshal’s Office and the FBI are involved in the investigation, and the National Transportation Safety Board also plans to send a team on Friday.