Abstract: At approximately 3:00 p.m. on August 2, 2002, Employee #1, a river guide for Tahoe Whitewater Tours, was guiding a river rafting trip down the Truckee River near Floriston, CA. The rafts were going through Class 3 rapids when they struck a submerged rock and turned about quickly. Employee #1 was thrown off balance, and because his foot was anchored in the bottom of the raft for balance, his kneecap was dislocated as he was turned about. Employee #1 was then thrown from the raft, but two of the passengers immediately pulled him back in. This was the last rapids at the end of the trip, and the passengers provided first aid, then drove Employee #1 to the Tahoe Forest Hospital in Truckee, CA, where he was treated and released two hours later.