The accident happened Friday morning near Broad and Venango in North Philadelphia.
Investigators said an ironworker fell from the tenth floor and landed on the fourth floor.
The 44-year-old man was rushed across the street to Temple University Hospital, but where he was pronounced dead.
Witnesses said the man's safety harness broke. Investigators are still trying to determine the official cause of the accident.
He was a worker for the Berlin Steel Construction company.