A Birmingham man's death is being investigated as a homicide, after initially being classified as a suicide.The Birmingham Police Department reports the incident happened at 2132 46th Place in Ensley about 8:00 a.m. this morning.When officers arrived at the scene, they found Keith Lamont Tolbert, 44, lying on the ground and unresponsive.Tolbert was pronounced dead at the scene.Investigators first believed the death was a suicide, but the police department says additional information prompted the detective to investigate as a homicide.No suspects are in custody at this time.If you have information which could help the investigation, call the BPD Homicide Unit at 205-254-1764.