BANGOR – An early morning fire that broke out Friday on Center Street burned a four-unit apartment building, temporarily trapping three tenants before they were able to escape.

“When we were on scene, there was already heavy fire coming from the back of the building and people on the roof,” Bangor Assistant Fire Chief Darrell Cyr said late Friday morning.

Leonard Martin III, 26, Nathan Rosenbeck, 26, and Meisha Rice, 22 – the third-floor tenants of 83 Center St. – survived quite a scare and luckily were not injured.

Two firefighters, however, received minor injuries while fighting the fire.

Investigators with the State Fire Marshal’s Office spent most of Friday afternoon trying to sort out what happened. They would not comment on their investigation, which Cyr said would continue over the weekend.

“We’re pretty certain of the point of origin,” Cyr said, “but we have no idea what the cause was.”

The fire started sometime before 5:30 a.m. About an hour after the building’s tenants were evacuated, they stood outside shivering on the sidewalk across the street, some still in pajamas, as fire crews from Bangor and Brewer closed a section of Center Street to battle the blaze.

Flames disappeared from the back of the dwelling, but smoke continued to billow from the eaves on the third floor. Water flooded down the stairs out the open front door, as firefighters tried to salvage what was left of the structure.

While the first- and second-floor tenants got out safely, the third-floor tenants had only one exit, and flames blocked it.

Leonard Martin’s brother, Todd Martin, 23, who lives across the street, heard a car horn shortly after 5 a.m. and went to his window to see what was going on.

“I looked outside, saw smoke and tried to call [my brother],” Todd Martin said at his apartment, where the rest of the tenants later gathered.

When Leonard Martin didn’t answer the phone, Todd Martin ran across the street to look for him. He went inside the building and started banging on doors.

Leonard Martin hadn’t heard his brother’s call, but did hear the car horn. Then he started to smell the smoke.

“I thought, no way, this is impossible,” he said later in his brother’s apartment.Leonard Martin ran from his apartment bedroom in the front of the building into the living room and saw flames out his entrance door shooting up the back stairwell. Martin and Rice tried to get out through the back, but weren’t able to.

When fire and police crews arrived, Martin and Rice were standing on the roof of the second-floor porch. They had climbed from their bedroom window but were unable to get down.

Rosenbeck, who lived in the same apartment, escaped through a second-floor window near the center of the building with help from a neighbor’s ladder.

“When you pull up to a scene like that and see live flames and people on the roof, our primary concern was the safety of these people,” Assistant Chief Cyr said.

Martin and Rice were sitting on the porch roof when crews arrived. Cyr said firefighters used a ground ladder to help the two tenants from the building.

Marie Reynolds, 22, who lived alone in an apartment on the second floor, escaped down the stairs and out the front door before fire crews arrived.

“I didn’t hear my [smoke] alarm,” she said while recovering in Todd Martin’s apartment.

“I saw smoke out my window and heard someone pounding on my door,” Reynolds added, solemnly looking down at the hooded sweat shirt and pants she was wearing. “This is all I have … I don’t even have my glasses.”

“We’re going to get a place for you,” Jody Roberts, a volunteer from the American Red Cross, told Reynolds.

Roberts and others from the Red Cross led Reynolds and the other tenants from the cold sidewalk into Martin’s apartment. They drank coffee and ate doughnuts, but looks of disbelief remained on their faces.

First-floor tenants Richard Marano, 31, and his wife, Sheri Marano, 26, also were able to get out safely. Their apartment was the least damaged of the four, but Cyr said the entire building is unlivable.

“I can’t believe this could happen” Richard Marano said. “There’s really not much you can say.”

The building is owned by Jeff Gray of Holden, who was at the scene Friday and later spoke to his tenants. He said the structure was “up to code.”

None of the tenants was hurt, but two Bangor firefighters were taken to a local hospital with minor injuries, Cyr said. He declined to release their names, but said late Friday that both had been released.

The building’s only other tenant, Victoria Ragonesi, 31, was not inside at the time of the fire. She arrived shortly after 8 a.m. and spoke with fire officials.

Vehicles owned by Ragonesi and Rice were parked on the side of the building and were damaged extensively by water and debris from the structure.