Firefighters are trying to figure out how an oxygen tank combusted inside of a home in North Haven and set that home on fire early Sunday morning.
The fire began in the front living room on the first floor of a single family home on Standish Avenue shortly after 3:30 a.m. It then spread to the second floor, firefighters said.
All five people that were inside of the home were able to escape safely.
It took firefighters about an hour to get the fire under control, but fire officials said the house is now uninhabitable.
The oxygen tank that exploded is used by one of the residents for medical needs.
Investigators are going through the rubble to determine what went wrong.
"A lot of this is a matter of interviewing all of the occupants of the home, trying to determine what they saw, what they did on their way out, and so forth, how they were alerted to the fire," said North Haven Fire Chief Paul Januszewski.
Fire officials said there is no threat to the community.