Pentagon and Arlington County emergency responders assemble in the Office of the Secretary of Defense conference room in the Pentagon for a mass casualty exercise (“MASCAL”). The exercise involves several mock-scenarios. One is of a commercial airliner crashing into the Pentagon and killing 341 people, while two others are a terrorist attack at the Pentagon’s subway stop and a construction accident. The plane crash exercise is conducted using a large-scale model of the Pentagon with a model airplane literally on fire in the central courtyard of the building. An Army medic who participates calls it “a real good scenario and one that could happen easily,” while a fire chief notes: “You have to plan for this. Look at all the air traffic around here.” [MDW News Service, 11/3/2000; Mirror, 5/24/2002; United Press International, 4/22/2004; 9/11 Commission, 7/24/2004, pp. 314]