An FBI official shed additional light Monday night on the deaths of two FBI agents who were killed while training Friday. The spokeswoman says Christopher Lorek and Stephen Shaw fell to their death during a counterterrorism exercise, when the helicopter from which they were “fast-roping” ran into difficulty, dropping them a “significant distance” from the ship below. A formal cause of death for the two will likely not be announced for weeks. The two men were members of the bureau’s elite rescue team—the same one that saved the 5-year-old boy who was trapped for days inside an Alabama bunker. "They're really the best of the best as far as civilians,” said Clint Van Zandt, a former FBI hostage negotiator.