Suffolk County police say they are investigating the accident, which occurred in Amityville around 8 p.m.
Police say 24-year-old Jorge Fernandez, of Copiague, was riding a 2003 Kawasaki motorcycle east on Dixon Avenue when the bike left the roadway and struck a building at 175 Dixon Ave. Fernandez was pronounced dead at the scene.
The bike was impounded for a safety inspection.
Anyone with information on this crash is asked to call the First Squad at 631-854-8152 or anonymously to Crime Stoppers at 1-800-220-TIPS. All calls will be kept confidential.