A Brooklyn man was pronounced dead after falling from his bike while riding over the Manhattan Bridge on Sunday afternoon, authorities said, though his actual cause of death remains unclear.

According to police, Philip Ginsberg, 36, was riding in the bridge's Brooklyn-bound bike path lane with a group of cyclists when he abruptly lost consciousness. A preliminary investigation found that he "fell off his bicycle and struck his head on one of the bridge's support beams." A police spokesperson told Gothamist that it's believed he suffered a medical episode.

Ginsberg, who was wearing a helmet when he fell, was unconscious when first responders arrived on the scene. He was subsequently transported to New York-Presbyterian Hospital Lower Manhattan hospital, where he was pronounced dead.

The Manhattan Bridge bike path remained closed for much of Sunday afternoon, but has since reopened.

The NYPD's Highway Patrol Collision Investigation Squad is looking into the incident. The city medical examine's office will perform an autopsy to determine the cause of death.

We'll update as more information becomes available.

UPDATE: Members of Philip Ginsberg's cycling team, some of whom were riding with him on Sunday, have released a statement remembering him as a "a sweetheart, [who] loved bike racing, was always positive and optimistic and was everybody’s 'mate.'"

They also noted that doctors indicated his death was caused by a cardiac event, and not from injuries sustained when he lost control of his bicycle. You can read the full statement here.