Swooping down from the north, American Airlines Flight 11 strikes the northern World Trade Center tower at 8:46 a.m. Observers on the ground, questioning what just happened, look up in disbelief.

News channels immediately begin broadcasting live coverage, many speculating the event was an accident. Such theories soon evaporate as United Airlines Flight 175 smashes into the southern tower at 9:03 a.m. on live TV.