The death has been ruled a suicide, according to Detective George Knight.
"He hit a little roof and then a car and landed on the sidewalk,'' said Hagerstown Fire Battalion Chief Ron Horn. "They found a Bible next to him.''
The man was transported to Washington County Hospital where he was pronounced dead at 8:12 a.m., according to hospital spokesman John Costopoulos.
Morning rush hour motorists experienced long delays as traffic throughout the downtown was disrupted by the incident.
In the Monday evening incident, a man who was critically injured when he fell from a window on West Antietam Street had earlier been embroiled in an argument with his girlfriend, a witness told Hagerstown City Police.
The fall victim remained in critical condition this morning at Washington County Hospital.
Lt. Roy Cave said investigators are planning to interview the man today to determine what happened.
Foul play isn't suspected, Cave said.
The witness in the apartment said the man was last seen kneeling by the window, Cave said.
A passing motorist, Sara Snyder, said she was leaving her job at District Court at about 6 p.m. when she saw a man falling in front of 21 W. Antietam St.
"I just saw him in mid-air," she said. "I've never seen anything like that in my life."
Snyder said she immediately hit her brakes and stopped her car in the parking lot across the street. She ran to the man while another passerby called 911.