On this day 61 years ago, on December 24, 1964 (November 21, 1964 lunar calendar), there was a big explosion in the US officers' dormitory building in Saigon. On December 24, 1964, a big explosion occurred in a seven-story US officers' dormitory in downtown Saigon. The spokesperson of the US invading army in Saigon announced that two Americans were killed, one of whom was a lieutenant colonel of the US invading army, and seventy-one people were injured, including fifty-five US officers. Western news agencies believe that the actual casualty figures are much higher, and that there may be more US casualties in the ruins of the building that have not yet been found. This building is a main officer dormitory of the US invading army in Saigon, and most of the people living there are colonel-level military officers. The American military authorities usually take precautions against the building: it is surrounded by a 15-foot-high concrete wall; there are pseudo-police guards in front of the gate; and searchlights have recently been set up around the wall. Western news agencies believe that the explosive that caused the explosion may have been a 500-pound bomb that was "apparently smuggled into the building." The explosion was reported to be the most powerful explosion in Saigon's history, destroying half of the building's nearly 100 rooms. The American radio station located on the ground floor of the building, as well as 24 cars placed near the building, were also destroyed. The fire caused by the explosion lasted for half an hour, and the sound waves of the explosion even shattered the windows of the United States Information Service 200 feet away from the building. When the explosion occurred, a group of American invaders living in the building were busy preparing to have fun on Nativity night.