A woman was found dead in a fire at a house in Easton, Massachusetts, investigators said Friday.

Easton Fire Chief Justin Alexander said firefighters were initially called to the home on North Main Street just after 9:20 p.m. Thursday for a medical emergency.

But when the fire engine and ambulance arrived, the single-family house was on fire.

"That would not be what we would send to a structure fire, if it came in as a structure fire. So, we were caught with a medical response to a structure fire and I'm absolutely proud of our staff and commend them for being able to jump into action, get their gear on and get to work quickly and get a strong response going," Alexander said. "First time in my career in over 20 years that a medical call has turned into a four-alarm fire."

The woman was found dead inside the home. There's no word yet on how she died. Her name has not been released. Alexander said she was the only person in the house at the time. Neighbor Matt Johnson said the woman had lived there for many years.

"I hadn't seen her much lately because she's wheelchair-bound and not doing much and her kids were there taking care of her," Johnson said.

The cause of the fire is also under investigation, but Alexander said it appears to be accidental. It took out about two hours to put out.

"The house layout was challenging. Very broken up, cut up house as far as the layout and created a lot of challenges for us inside," Alexander said.

There was also a brief mayday call.

"We had a firefighter get caught up in some debris in the corner and they were able to free themselves with the help of another firefighter," the chief told reporters.

Easton, Massachusetts is 28 miles south of Boston and 28 miles northeast of Providence, Rhode Island.