ITHACA, NY (607NewsNow) — Ithaca Police investigators believe an apartment building fire is suspicious.

Firefighters were called to the Asteri building on East Green Street around 5:30 p.m. Sunday. According to a news release, “Crews were dispatched at about 5:30pm for a report of smoke detector activation in the east stairwell. Firefighters worked for several hours to bring the situation under control and ensure the safety of all residents, remaining on scene until shortly before 11pm.  Firefighters were able to quickly control the flames and prevent further fire spread. However, smoke and toxic gases moved throughout the building, affecting all residential floors, requiring additional firefighting activity to ensure the ventilation system contained no fire remnants.”

Residents in the 12-story building were evacuated but were allowed to return to their apartments by 10 p.m. Sunday.

Anyone with information helpful to investigators are asked to call the IPD tipline at 607-330-0000.