SLIPPERY ROCK — A garage fire early Sunday morning forced a half dozen tenants to flee their homes at a four-unit apartment building near the Slippery Rock Plaza, authorities said.

One person was treated for minor smoke inhalation but no other injuries were reported in the fire on Arlington Drive in Slippery Rock. One cat died.

The blaze caused about $100,000 in damage.

The state police fire marshal’s office has been called in to investigate but the blaze is not believed to be suspicious, said Chief Ken Taggart of the Slippery Rock Volunteer Fire Company.

“My guess is it was electrical because there was heavy fire damage by the electrical panel” in the garage where it started, he said.

About 30 firefighters from five departments were called about 2:20 a.m. to the apartment building off Kelly Boulevard about one-quarter mile northwest of the Slippery Rock Plaza.

Suellen McCollin, who lives in neighboring Kelly Farm apartments, said she was reading when she heard a noise and saw the flames.

Taggart was there five minutes after the first 911 call.

“There was heavy fire coming from the garage of one of the units,” he said. “It was fully involved and into the attic of the apartment.”

The building, owned by Pascoe Builders of New Castle, has four units each with an attached garage all on one floor.

All four apartments are leased and the tenants of three of those units, each with two people inside, were home but got out safely.

However, authorities did not immediately know if anyone was still in the fourth unit.

Taggart said firefighters forced in the door to the apartment and a search crew sent inside confirmed no one was there except a cat, which apparently became scared in the chaos.

“It must have panicked and hid, and got stuck,” Taggart said. The cat reportedly was later found dead inside.

Two engines and a ladder truck from the Slippery Rock fire department complemented fire crews. The Harrisville Volunteer Fire Department provided a third engine and the Grove City Volunteer Fire Department assisted with a second ladder truck.

Additionally, the Pine Township Engine Co. of Mercer County sent a rescue squad and the Unionville Volunteer Fire Department arrived with an air truck.

The fire was under control within 20 minutes, fire officials said.

“They did a good knock down on it,” Taggart said of firefighters.

Most of the fire damage was confined to the garage and a portion of the apartment at the unit where the blaze started. A motorcycle was among the property lost in the garage.

A resident at that apartment suffered smoke inhalation. Slippery Rock Ambulance treated that unidentified tenant, who refused further treatment.

The remaining apartments sustained minor smoke damage. The tenants of those units were allowed to return, fire officials said.

Taggart said he believes the unit where the fire broke out would have to be replaced. The tenants there are staying with relatives or friends nearby

The property is insured, and all the tenants have renter’s insurance, authorities said.

A deputy fire marshal at the Butler barracks is to begin his investigation Tuesday or Wednesday.