PORTLAND — An early morning apartment building fire appears to be accidental but remains under investigation today.

The fire at 52 Federal St., reported at 1:21 a.m., was concentrated on the third floor. The fire had gotten  between the ceiling and the roof and was burning intensely, Fire Department Deputy Chief David Jackson said.

The five occupants home at the time got out of the three-story, three-unit building safely. No firefighters were injured.

Firefighters had to put two vents into the roof. It took about an hour to get the fire under control.
The fire investigation team is back at the scene. The cause of the fire is not yet known.