Eleven advertising executives from some of the largest corporations in the United States boarded a raft for a day of river running in British Columbia. Less than three hours after they pushed off from shore, five of them would be dead. No one knows exactly what happened that day, but the bow of the raft caught an errant current, turned abruptly, and then unexpectedly careened into a rock mid-stream. All but one of the men were dumped into the tortured...