By Nadine Yousif,BBC News
Five US Marines who died in a helicopter crash while flying from Nevada to California earlier this week have been identified.
The helicopter, a Marine Corps CH-53E Super Stallion, went missing on Wednesday and was later found in a mountainous area of California.
The helicopter was on a training flight from a Nevada Air Force base to an air station near San Diego.
The cause of the crash is still being investigated.
Officials said its last reported location was received on Tuesday evening at about 23:30 local time.
The helicopter was later found in the snow-covered California mountains - about 45 miles (74km) from its destination.
"It is with a heavy heart and profound sadness that I share the loss of five outstanding marines from 3d Marine Aircraft Wing and the 'Flying Tigers," Maj Gen Michael J Borgschulte, commander of the 3rd Marine Aircraft Wing, said in a statement on Thursday.
All five marines on board the helicopter were later identified as Lance Cpl Donovan Davis, 21, Sgt Alec Langen, 23, Capt Benjamin Moulton, 27, Capt Jack Casey, 26 and 28-year-old Capt Miguel Nava.
"We have been confronted with a tragedy that is every service family's worst fear," the commanding officer of the Marine Heavy Helicopter Squadron 361, their unit, said in a statement.
"Our top priority now is supporting the families of our fallen heroes, and we ask for your respect and understanding as they grieve," he added.
"The Flying Tigers family stands strong and includes the friends and community who have supported our squadron during this challenging time. We will get through this together."
President Joe Biden offered his condolences to the families of the troops after the news broke on Thursday morning.
"Our service members represent the very best of our nation - and these five marines were no exception," Mr Biden said in a statement.
All five service members were assigned to the unit, which forms part of the 3rd Marine Aircraft Wing.
They had departed for Marine Corps Air Station Miramar in San Diego late on Tuesday following a training at Creech Air Force Base near Las Vegas.
The Marine Corps said that the helicopter was reported overdue at 01:00 local time (08:00 GMT) on Wednesday. Fire crews were then alerted to the missing aircraft shortly thereafter at 02:20 local time.
The crews were dispatched to an area near Lake Morena, California. They were able to locate the aircraft hours later near Pine Valley, California, in the Cuyamaca Mountains.
Search efforts were hindered by heavy snow and wintry conditions in the area, officials said.
The incident comes in the wake of a powerful winter storm in the region that dumped heavy rain and several inches of snow in mountainous areas.
The CH-53E Super Stallion is among the largest helicopters used by the military. Over the past three decades, it has often been brought in for heavy-lifting operations.
But it has a chequered safety record, and there have been several serious accidents involving the helicopter in recent years.
In April 2018, four troops were killed when their Super Stallion crashed near El Centro, California, while on a training mission.
In a separate incident in January 2016, 12 marines were killed when two Super Stallions collided over the Pacific near Oahu in Hawaii.
