SAN DIEGO — The U.S. Navy has declared five missing sailors dead five days after a helicopter crashed in the ocean off San Diego dead and has shifted the search for them to a recovery operation.

The change in operation comes after more than 72 hours of coordinated rescue efforts and nearly three dozen search and rescue flights, the Navy’s Pacific fleet said in a statement issued Saturday.

The names of the sailors were being withheld until their next of kin have been notified.

An investigation into what caused the crash about 70 miles (112 kilometers) off San Diego is ongoing.

Also injured were five other sailors who were on board the USS Abraham Lincoln aircraft carrier where the MH-60S helicopter was operating on the deck before the crash.