HOUSTON -

An elderly man was killed in an apartment fire in southeast Houston.

Houston police and firefighters went to the Park Houston apartment complex in the 120000 block of Martin Luther King Jr. Boulevard just before midnight Thursday after a fire broke out in a second-floor unit. 

Inside the unit, detectives said they found Casimiro Ibarra Compean, 82, dead on a mattress on the floor.

Police said they believe the death was accidental.  Homicide investigators said the man may have fallen asleep with a lit cigarette in his hand, which sparked the blaze.

The medical examiner will determine the exact cause of Compean's death.