SAN DIEGO, California – Five US Marines were confirmed dead after their helicopter crashed in a remote area outside of San Diego while on a training flight during a fierce winter storm, the United States Marines Corps said on Feb 8.

Their CH-53E Super Stallion helicopter went down in Pine Valley, a hilly remote area east of the city, on Feb 6 as it was headed to the Marines Corps Air Station in Miramar, California.

The remains of the crew members were found during a search and rescue effort carried out by the Marines and the local authorities.

“It is with a heavy heart and profound sadness that I share the loss of five outstanding Marines,” Major-General Michael Borgschulte said in the statement.

In a statement, US President Joe Biden offered his condolences to the families of the five Marines, saying he and First Lady Jill Biden were “heartbroken at the loss”.

The Marines Corps said it was waiting until after the families of the crew members were notified before releasing their names.

The helicopter departed from the Creech Air Force Base in Nevada about 60km north-west of Las Vegas on Feb 6 and flew into rainy and snowy weather as it headed west. About eight hours later, it was reported overdue.

It was unclear what caused the crash. An investigation is under way. REUTERS