A vacant building collapsed after a suspicious fire broke out inside of it Friday morning, officials say.

Flames erupted on the first floor of the building at 725 E. 141st St. and spread next door.

Officials say they believe the fire was intentionally set. 

Neighbors say the building is largely abandoned but report seeing squatters frequently.

Fire investigators say the adjacent building, which is also abandoned, faces the risk of collapse as well, and authorities have cordoned off the area.

Investigators say they don't believe anyone was inside at the time of the fire, but they will perform a search as a precaution.

The departments of Buildings and Housing Preservation and Development will also join the investigation.