美国将一次死亡 5人 (含 )以上的居住建筑火灾和一次死亡 3人 (含 )以上的非居住建筑、非建筑火灾定义为造成重大人员伤亡的火灾。 2 0 0 1年 ,美国共发生5 37起此类火灾 ,造成 2 975人死亡——其中 2 791人死于 2 0 0 1年 9月 11日恐怖分子劫持飞机撞击纽约世界贸易中心双塔和 In the United States, one residential building fire with more than 5 deaths per person and one non-residential building with more than 3 deaths per person at one time, the non-building fire was defined as a fire causing heavy casualties. In 2001, a total of 5 37 such fires occurred in the United States, killing 2 975 people - of whom 2 791 died. 11 September 2011 Terrorist hijacking aircraft hit the twin towers of the New York World Trade Center and