By the time the Vietnam War ended in 1975, tens of thousands of tons of explosives had been dropped on Hanoi and nearly two decades of fighting had killed 3 million Vietnamese and more than 58,000 Americans. Vietnam, though victorious, lay devastated by American firepower, with cities in ruins and fields and forests soaked in toxic herbicides and littered with unexploded ordnance. IN PIC: n this March 1966, file photo, a US Air Force B-52 delivers a bomb load of more than 38,000 pounds against Viet Cong strongholds in South Vietnam. (Photo | AP)