A two-alarm blaze that damaged the El Sobrante Library on Tuesday night has been deemed suspicious by fire officials.
The fire was first reported at 8:20 p.m. at the library at 4191 Appian Way.
The blaze started externally before spreading to the library roof, Contra Costa County Fire Protection District Capt. George Laing told media outlets.
The fire appears to have been started by homeless people setting a porta potty ablaze that was next to the building, said Doug Parker, systems facilities manager for the Contra Costa County Public Works Department.
The cause of the fire remains under investigation, fire officials said.
The extent of the damages was not immediately clear, but the library is expected to remain close for weeks if not months for repairs, Parker said.