A San Diego-based MH-60S Nighthawk helicopter crashed in the Red Sea with two crew members on board Sunday. The navy search was called off Monday and the two are apparently lost at sea.

Navy officials said they concluded "aircrew survivability was extremely unlikely," given the time that had passed since the accident off the west coast of Saudi Arabia.

The chopper, assigned to Helicopter Sea Combat Squadron 6 at Naval Air Station North Island, crashed while the pilot trying to land on deck of the San Diego-based guided-missile destroyer USS William P. Lawrence. Both deployed with the USS Nimitz Carrier Strike Group in January.

There was nothing to indicate it was any kind of terrorist activity. Three of the helicopter's five crew members were "accounted for and stable" following the crash.