Two FBI Agents Killed in Training Exercise

Incident is under review

(CNN) -- The FBI is mourning the deaths of two special agents killed Friday during a training exercise off the coast of Virginia Beach, Virginia.

The agents, Christopher Lorek and Stephen Shaw, were assigned to the FBI's Critical Incident Response Group. The FBI said the cause of the incident is under review.

"We mourn the loss of two brave and courageous men," FBI Director Robert S. Mueller said in a statement issued Sunday.