From the Mind of Trevor Stone

At 9:40 a.m. on Saturday, July 28, 1945, a B-25 Mitchell bomber, piloted in thick fog by Lieutenant Colonel William F. Smith, Jr., accidentally crashed into the north side of the Empire State Building, between the 79th and 80th floors, where the offices of the National Catholic Welfare Council were located. One engine shot through the side opposite the impact and fell on a nearby building; the other plummeted down an elevator shaft. The resulting fire was extinguished in 40 minutes. Fourteen people were killed in the incident. Elevator operator Betty Lou Oliver survived a plunge of 75 stories inside an elevator, which still stands as the Guinness World Record for the longest survived elevator fall recorded. Despite the damage and loss of life, the building was open for business on many floors on the following Monday.
-- Wikipedia

I wonder why I never heard this mentioned after the September 11, 2001 attacks. I guess the analogies to Pearl Harbor (where enemy planes hit a U.S. landmark) were more resonant than this incident where a U.S. Army plane hit a New York landmark.