Fire claimed an apartment and two pet birds at Knoxview Apartments Wednesday, Jan. 27, around 6:30 p.m., according to Bucksport Deputy Fire Chief Michael Denning.

Authorities aren’t sure how the fire started but think it began in the kitchen, the deputy chief said, adding, “It’s still under investigation.”

“We had a report of a smoke detector going off,” Denning said. “It was on the two-story section. It burned the apartment up pretty good.”

No one was injured, but people did have issues exiting the building.

“We had reports of people trapped in the second-floor area and the stairwell,” said Denning. “At that point, arriving firefighters went in on the stairwells to evacuate people.”

There was smoke throughout both sides of the buildings, including into the third floor and a bit into the fourth story of the complex.

Crews were on scene for about four hours.

“They knocked the fire down pretty quickly, but it was a lot of work afterwards for smoke,” Denning said. The department uses a carbon monoxide detector to make sure a living area is safe after a fire.

“First we ventilated the halls and then the stairwells and then the individual apartments, so it was quite time-consuming,” Denning said.

A second ladder truck was borrowed from the Ellsworth Fire Department in addition to the department’s ladder truck. Fire departments from Orland, Dedham and Orrington assisted.