What started out as an adventurous holiday for a clients of a top-level advertising agency ended in tragedy when their raft overturned in "the White Mile", a continuous stretch of big rapids on British Columbia's Chilko River. The rapids in Lava Canyon, which drop 45 feet per mile, are rated Class V at high flows. The group was running in a single 18' raft which broached on a midstream rock and tipped high, throwing all but one of the entire crew into the river. Some held onto the raft; some swam ashore. Five high-level corporate executives were carried downstream a great distance and did not make it ashore alive. The guide ran upstream to his camp and returned with a second boat to pick up survivors.
Source: Innumerable newspaper and wire service articles1) The rafting outfitter was an experienced man with a good reputation who allowed himself to be pressured by an important client into loading the entire party into a single raft. He was also pressured, against his better judgement, to permit the men to raft without wetsuits. Commercial guests often ask outfitters to cut corners on safety, and when it's a small outfitter and a big client thast pressure can be severe. This incident shows that inadequate equipment and a breakdown in safety procedures can lead to tragedy even when the outfitter is otherwise quite skilled.
2) Theis was a one-boat trip. Since the outfitter did not provide a chase boat there was no backup. When his raft flipped, the guests were on their own. I personally feel that one-boat trips should not be run by outfitters on whitewater over Class III because it makes rescuing people quickly after a mishap quite difficult. This could be a second oar-rigged boat or a safety kayaker.
Postscript: All of the victims were big corporate earners, and the outfitter was a small guy with a few rafts and a pickup truck. They elected to sue the advertising agency, which was responsible for telling the guide not to take appropriate safety precautions. They won considerable money, and the accident sent tremors through the rafting industry.