It was a counterterrorism training exercise that two agents from the Federal Bureau of Investigation's elite hostage rescue unit had completed dozens of times: rappelling from a helicopter onto the deck of a ship at sea, says the New York Times. As agents Christopher Lorek and Stephen Shaw began their descent on Friday onto a ship off the coast of Virginia, the helicopter suddenly tilted because of a strong gust of wind. As the pilot tried to steady the aircraft, the two men, holding ropes and loaded with gear, lost their grips and fell. It was the first time an agent died in the line of duty since December 2011. In the past 12 years, six others have been killed. The FBI has 14,000 agents. The hostage rescue unit was created before the 1984 Summer Olympics in Los Angeles to help the government respond to an episode similar to the one at the 1972 Olympics in Munich, in which 11 Israeli athletes were killed after being taken hostage. The unit, with fewer than 100 agents, has responded to 850 episodes, including the bombings at the Boston Marathon.