The seven Marines and four soldiers whose helicopter crashed during a training mission near Eglin Air Force Base in Florida are all presumed dead.
A Pentagon spokesperson confirmed the tone of the search and rescue, which began early Wednesday morning, had shifted and few now expected survivors. Sara Vidoni, a military spokeswoman for Eglin, meanwhile, said human remains had washed ashore, The Associated Press reported.
It's not clear why the crash occurred, but officials in the area said weather could have been a factor, Fox News reported.
Andy Bourland, a spokesman for the Florida Panhandle base, said crews first found debris from the crash around 2 a.m., hours after the actual wreck occurred, AP reported. The names of the crash victims have not yet been released, pending notification of family.
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The Marines aboard the Blackhawk were part of a special operations group based in Camp Lejeune, N.C., while the soldiers came from a National Guard unit out of Hammond, La., Fox News reported.
The chopper went down on a beach located between Pensacola and Destin that's owned by the military and used as a test site.