Mystic ― The Mystic fire department extinguished a fire at a two-family home on Stanton Lane on Thursday afternoon, 20 hours after putting out another house fire on Route 27.

No one was injured in either fire, but both homes were damaged as a result of firefighters having to open up walls to stop the fires from spreading.

The department responded to the first fire just before 6 p.m. Wednesday at a duplex at 11 Greenmanville Ave. Mystic Fire Chief Christopher Clarkin said the fire burned for two to three hours before a resident reported it.

Three residents were temporarily displaced, according to a release from the American Red Cross, which assisted them.

Clarkin said when firefighters arrived, a resident was putting water on the fire to keep it in check. Small flames and a “fair amount of smoke” were coming from a section of the home.

“We actually found out, through our investigation and interviews the police conducted there was a person who was burning weeds on the property,” Clarkin said. “Some of that continued to smolder, and got underneath the siding and continued to smolder for some time.”

Firefighters had to make some holes in the walls, from the basement up to the attic to reach the fire, Clarkin said.

The fire was extinguished in about an hour, Clarkin said.

There was “fairly extensive” damage to the second-floor bathroom from the fire and from water damage.

The Old Mystic and Sub Base fire departments along with Lawrence + Memorial Hospital paramedics and Mystic River Ambulance also responded to the fire.

Thursday’s fire at 38 Stanton Lane was similar, Clarkin said. It had started with a resident burning weeds outside.

But this time, the resident reported it right away. Firefighters responded at 1:52 p.m. When they got there, there were flames coming from the corner of the house with smoke coming from all levels of the house and attic and out the front door.

Clarkin said firefighters had to pull out a lot of the walls to make sure the fire, which was in the homeowner’s office area, wasn’t spreading. There was also water damage.

The fire was extinguished within 30 minutes. Crews from the Old Mystic, Poquonnock Bridge, Ledyard and Sub Base fire departments responded.

Clarkin said the homeowners were able to close off the damaged part of the home and occupy the other half. He said some of the firefighters were treated for possible heat exhaustion.

d.drainville@theday.com