A three-alarm fire caused an estimated $500,000 in damage to a vacant apartment building in East Boston, the Boston Fire Department said on its Twitter account.
No one was injured and firefighters said no squatters were found living inside the building.
Crews responded to 201 Marion St. at 2:11 a.m., the department said. Heavy fire was found in the three-story, three-unit wood frame building on arrival, officials said.
The cause remains under investigation.