DETROIT -- Careless smoking may have started a fire that took the life of a 90-year-old man Tuesday morning, said fire investigators.

When firefighters responded to a fire on Dorris Street around 4 a.m. on Detroit's northwest side, they found an elderly the man dead in a reclining chair on the second floor.

Investigators said the man fell asleep while smoking a cigar. A fire alarm was installed in the man's room, but it had no batteries in it, said fire investigators.