What event happened at Washington monument?

On October 28, 1974, a B-52C Stratofortress bomber carrying four hydrogen bombs crashed into the ground near Damascus, Arkansas, following a mid-air collision with a KC-135 Stratotanker. Three of the bombs were damaged, and one narrowly avoided detonation after its three arming mechanisms were armed but failed to detonate. Some reports claim that it came within feet of detonating. If the bombs had detonated, the resulting blast would have created an explosion equivalent to 100 kilotons of TNT, roughly seven times the yield of the atomic bomb that leveled Hiroshima, with potentially catastrophic consequences for the region and beyond.