A U.S. Navy submarine and an Aegis class cruiser that collided somewhere off the East Coast are both back in port and officials are investigating what went wrong. The submarine USS Montpelier arrived at Naval Submarine Base Kings Bay in southern Georgia. The USS San Jacinto arrived at Naval Station Mayport in Jacksonville, Fla. on Sunday. Navy officials say they collided at about 3:30 p.m. Saturday during routine training operations. No one was injured.