On the afternoon of August 23rd, four friends who were rafting together on the rain-swollen Delaware River fell out of the raft when it hit a standing wave in Staircase Rapids and flipped over. Only one of the raftâs occupants was wearing a lifejacket at the time. He and two others were able to swim ashore, but Hin Hon Siu, 36, of Flushing, New York, swam downstream. Ranger Kevin Reish and park VIP Robert Hare were on boat patrol not far downstream at the time. When they received a visitor report of people in the water, they responded, spotted Siu, and threw a flotation device to him. Siu was barely above the waterline, though, and was unable to utilize it. Hare jumped into the river in an attempt to save Siu, but Siu slipped below the surface of the swollen and muddy river and disappeared. An interagency search was begun, but no sign of Siu was found. The search is still underway.