A lit candle left unattended in the second-story bedroom of an Atlantic Townhouse apartment building caused a fire Sunday afternoon that displaced a woman and her three teenage sons.

The Red Cross was helping Beth Grasser and her children with clothing and a place to stay, Fire Chief Steve Hinds said this morning.

Investigators with the State Fire Marshal’s office determined the fire at 12 Central Ave. was caused accidently, Hinds said. Hinds said today that windows were left open in the bedroom, and that the candle might have fallen over onto combustible material.

The fire was reported around 12:15 p.m. at the home of Grasser, who lived in one of two middle units in the six-unit 1940s-era brick building.

“The second floor was fully involved when we got here. It took 30 to 45 minutes to knock it down. It was a multiple-line attack. Everybody got some work out of this one,” Hinds said.

Hinds said that the second floor was burned out, but the first floor was not badly damaged.

“This is going to be repaired,” he said.

West Bath and Brunswick fire departments, who respond automatically to Bath fire calls, were at the scene as well.

Grasser had gone with her 13-year-old son to get groceries at Walmart around 11:30 a.m.

“They’d been trying to call, but I had no reception till I got to the car and (my neighbor) Ardelle said, ‘Your house is on fire,’” Grasser said as neighbors carried her waterdamaged belongings out of the apartment and onto the lawn.

A 16-year-old son had been fishing and 18-year-old Nathanial was visiting friends on Union Street.

Grasser’s youngest son left a candle burning in his bedroom. “He was in such a rush to come with me. He cried on the way back and said he was sorry. I said that’s why it’s called an accident,” Grasser said.

Ardelle Ballou, who lives at 14 Central Ave. in the apartment immediately next door, believes she was the first to call 9-1-1.

“I smelled smoke. Then I saw smoke coming out of the bedroom window,” Ballou said. She and her two young children were the only tenants at home when the fire started.

Central Avenue residents Stephen Ambrose and Edward Borges, unsure if anyone was trapped inside, rushed to assist their neighbors. “I kicked the door in. I made it upstairs. Made sure no one was in there. Then got out. It was rough,” Ambrose said.

Two of Grasser’s cats escaped when Ambrose entered the building. Two other pets, a rabbit and a kitten, were rescued later. The kitten was taken to the emergency room for smoke inhalation, Grasser said.

The fire started in a bedroom at the rear of the apartment and extended into attic space, Hinds said. The second floor was destroyed and the first floor sustained water damage only. Hinds estimated the damage at $20,000 to $30,000.

Abutting apartments were not damaged by the fire, but the fire department cut a hole in one of her walls, Ballou said.

The Red Cross was at the scene to provide assistance to the Grasser family, who will stay at an area hotel for a few days. According to Grasser, her landlord has other units available and would “speed it along” so she would have a place to stay.

rshelly@timesrecord.com