(Reuters) – Seven Marines and four soldiers were presumed dead after an Army Black Hawk helicopter crashed during a nighttime training mission off the Florida coast, where some human remains have washed ashore, U.S. military officials said on Wednesday.
A spokeswoman for the Eglin Air Force Base in north Florida did not provide details on the remains and officials did not immediately release information on what might have caused the crash.
Local media showed images of what appeared to be helicopter parts and base officials asked nearby residents to report any findings.
The military in the morning called the effort a « search and rescue mission. » Heavy fog in the morning hampered the search.
One of two UH-60 Black Hawk helicopters participating in the routine exercise crashed near the base 50 miles (80 km) east of Pensacola, and rescue workers discovered debris about 2 a.m. EDT on Wednesday, the base said in a statement.
A U.S. military official, speaking on condition on anonymity, said the 11 service members aboard were presumed dead in what could be among the deadliest domestic military training accidents in years.
Eglin officials said the helicopter was believed to have gone down in the water. It was reported missing around 8:30 p.m. EST on Tuesday, when heavy fog had blanketed the region.
The Marines were part of a special operations unit from Camp Lejeune in North Carolina.
Four crew members and the helicopter were part of the Louisiana National Guard, assigned to an Army unit based in Hammond, Louisiana.
The second helicopter landed safely, the military said. Names of the missing troops were being withheld pending notification of next of kin.
President Barack Obama phoned military officials to express condolences, White House spokesman Josh Earnest told reporters, noting the president anticipated a detailed investigation.
General Martin Dempsey, the top U.S. military officer, said at U.S. Senate hearing that the “loss of the folks on that helicopter” served as « a reminder to us that those who serve put themselves at risk both in training and in combat. »
In February 2012, seven Marines were killed when two helicopters collided during a nighttime training exercise along the California-Arizona border.
The following year, another seven Marines died in an explosion at a Nevada munitions depot, after a mortar round detonated prematurely during a live-fire training exercise. Eight other servicemembers were injured in that incident.
The latest incident occurred near an Air Force base spanning nearly 500,000 acres in the Florida Panhandle that is used extensively for training.
(Additional reporting by Suzannah Gonzales, Phil Stewart, Curtis Skinner, Jonathan Kaminsky and Roberta Rampton; Editing by Susan Heavey, Doina Chiacu and Bill Trott)