An early morning fire caused heavy damage to a six-unit apartment building on Portland’s Forest Avenue Tuesday.

Firefighters remained on the scene at 732 Forest Ave. for several hours Tuesday morning to investigate the cause of a fire that started in a storage in the rear of the building. Photo courtesy of WCSH

Firefighters remained on the scene at 732 Forest Ave. for several hours Tuesday morning to investigate the cause of a fire that started in a storage in the rear of the building. Photo courtesy of WCSH

Firefighters were called to 732 Forest Ave. at 1:25 a.m. and arrived five minutes later, according to the Portland Fire Department.

Five of the six units in the buildings were occupied. All of the residents who were home escaped unharmed, including some pets.

First-floor resident Brent Tibbetts, 26, said he arrived home around 1:30 a.m. and saw firefighters directing streams of water into the building.

“I was driving up … and saw flames shooting out of the windows,” Tibbetts said.

The heaviest fire damage was centered in a rear storage area on the second and third floors.

Another first-floor resident, Elizabeth Chaplin, 22, was waiting to get back into her room to assess what of her belongings could be saved.

“There’s a lot of water damage on the ceiling and puddles on the floor,” Chaplin said.

Chaplin said she was not yet asleep when she smelled smoke and heard a roommate cry out that the building was on fire and heard the smoke alarms upstairs start beeping. She said the next thing she knew, there was a police officer in her apartment, helping to usher her out of the building.

Fire Capt. David Petrucelli said the building may not be a total loss. Fire officials said they do not believe the fire is suspicious, but have not yet pinpointed its origin or cause.

The Red Cross said it was called in to assist with relief efforts, and residents had not been allowed back inside as of early Tuesday morning.

A local Red Cross team assisted five residents who were affected by the fire, and plans to offer financial assistance and referrals for help.