In the 1990s, the U.S. intervened in Somalia as part of UNOSOM I and UNOSOM II, a United Nations humanitarian relief operation[84] that resulted in saving hundreds of thousands of lives.[85] During the 1993 Battle of Mogadishu, two U.S. helicopters were shot down by rocket-propelled grenade attacks to their tail rotors, trapping soldiers behind enemy lines. This resulted in a brief but bitter street firefight; 18 Americans and more than 300 Somalis were killed.