Two FBI agents died during a hostage rescue training exercise off the coast of Virginia Beach, a spokeswoman for the bureau said Sunday. Special Agents Christopher Lorek and Stephen Shaw were killed, but the FBI has so far declined to release any further information about the accident, which took place on Friday. Director Robert Mueller released a statement, praising the men for their courage. “Like all who serve on the Hostage Rescue Team, they accept the highest risk each and every day, when training and on operational missions, to keep our nation safe,” Mueller said. Both agents were based in Quantico, Va.