A list of some of the deadliest military aircraft crashes involving American troops in the U.S. and abroad over the past three decades:
JULY 10, 2017: Sixteen people killed when a KC-130 air tanker crashed outside the small town of Itta Bena in the Mississippi Delta while carrying members of an elite Marine unit cross-country for training.
MARCH 10, 2015: Eleven killed when an Army Black Hawk helicopter crashes into the water off Eglin Air Force Base, Florida.
AUG. 6, 2011: Insurgents shoot down a Chinook helicopter in eastern Wardak province in Afghanistan, killing 30 American troops, mostly elite Navy SEALs, along with seven Afghan commandos and a translator.
AUG. 22, 2007: A UH-60 Black Hawk helicopter crashed in northern Iraq, killing all 14 U.S. soldiers aboard. The military said it appeared the aircraft experienced a mechanical problem.
JAN. 20, 2007: A Black Hawk helicopter crashed in Iraq's Diyala province northeast of Baghdad, killing 12 American soldiers aboard.
JAN. 26, 2005: A CH-53 Sea Stallion transport helicopter crashed in a sandstorm in western Iraq, killing 30 Marines and a U.S. sailor.
NOV. 15, 2003: Two Black Hawks crashed in Mosul in Iraq, killing 17 soldiers. The military said the helicopters collided during a likely rocket-propelled grenade attack.
MARCH 8, 1988: Seventeen killed when two Army helicopters collide during a nighttime train mission near Fort Campbell, Kentucky.