San Francisco International Airport, the original destination of Flight 93, the fourth aircraft to be hijacked in the morning’s terrorist attacks, is evacuated except for essential personnel and shut down. [Associated Press, 9/11/2001; CNN, 9/12/2001] About 3,000 people are evacuated from the airport. [Associated Press, 9/12/2001; Los Angeles Times, 9/12/2001] Bomb-sniffing dogs patrol the hallways. [Associated Press, 9/11/2001] While the other major Bay Area airports are also shut down, only San Francisco Airport evacuates its terminals and closes its access roads. [Santa Rosa Press-Democrat, 9/12/2001] Security is heightened at many US airports, but the security precautions are particularly high at the San Francisco and Los Angeles airports (see 12:04 p.m. September 11, 2001), since these were the intended destinations of the four hijacked aircraft. [Associated Press, 9/11/2001; Los Angeles Times, 9/12/2001]