PITTSBURGH — Mark Schneider, a real estate developer who pushed for the development of Heinz Field, PNC Park, and the David L. Lawrence Convention Center in Pittsburgh, has died during an accident on a bicycle trip in western Maryland. He was 55.

Officials with Schneider’s firm, Fourth River Development, have confirmed his death but say few details are known.

Schneider was on a bicycle trip with his son, Max, when he had an accident Saturday near Thurmont, Md. Schneider died Sunday at the University of Maryland Shock Trauma Center in Baltimore.

Schneider pushed for the stadium development as chairman of the city-county Sports & Exhibition Authority and is well-known for his work on other landscape-changing projects in Pittsburgh including Summerset, an upscale housing development built on a former slag heap.

Funeral arrangements are incomplete.