A FBI spokeswoman says two agents who died while training off the Virginia Beach coast fell to their deaths during a "maritime counter-terrorism exercise involving helicopters and a ship."

The agents were part of the agency's elite hostage rescue team, a group known most recently for rescuing an Alabama boy from a kidnapper in an underground bunker.

Special Agent Ann Todd, an FBI spokeswoman, wrote in an email Monday night "the agents were in the process of fast-roping from the aircraft onto the ship when the helicopter encountered difficulties."

She said "the agents tragically fell a significant distance and suffered fatal injuries."

The deceased special agents have been identified as Christopher Lorek and Stephen Shaw. The state medical examiner's regional office is waiting for toxicology results.