Southold Town police don't believe a fire that ravaged a Mattituck building, killing one man, is suspicious, the department's chief said Monday.

"I don't think there is any reason to suspect foul play or to believe it was suspicious in nature," Chief Martin Flatley said of the blaze at 12800 Main Rd.

advertisement | advertise on newsday

The fire, which swept through the single-story building that contained two apartments and four businesses, began about 10:30 p.m. Friday and continued into Saturday morning. Paul Mittleman, 51, a tenant in an apartment, was killed, police said. Flatley said the Suffolk County police arson squad is investigating.

Firefighters extinguished the blaze at 1:52 a.m. Saturday, authorities said, with Mattituck Fire Chief Vincent Tirelli Jr. describing the fire as "stubborn."

A Jamesport firefighter had a foot injury, Tirelli said.

Most of the building's roof collapsed, and blackened shingles and beams littered the interior and an adjacent parking lot Saturday. The fire appears to have originated in Mittleman's apartment, police said.