Fire crews were called to the former Best Inn Hotel on Broadway at 7 p.m. after someone spotted flames coming from a first-floor room, according to Everett Fire Department investigator Eric Hicks.
Crews arrived moments later and made quick work of the fire, which was contained to a single unit.
Investigators are stilling trying to sort out what caused the blaze, but firefighters did find a man in the unit next door. That man is now being questioned, but Hicks said there's nothing to suggest the man is responsible for the fire.
"At this point it doesn't seem that he was the one who started the fire, but he's being interviewed by our investigators," he said.
A December fire at the same building is also under investigation. There were no injuries.