Immediately following the attack, a state of emergency was declared in the city, all federal office buildings were closed including the Pentagon, where roughly 23000 military and civilian personnel work. Security guards carrying automatic weapons were reportedly seen patrolling the White House grounds.

The attack, which is said to have taken place on the army side of the Pentagon, occurred at 9:45 a.m. yesterday. A hijacked American Airlines commercial aircraft, believed to be a 767 en route from Dulles International Airport to Los Angeles, crashed into the building, sparking a massive fire that burned throughout the day. A portion of one side of the building collapsed in the fire and a series of secondary explosions were reported in the area following the attack.

Government officials returned to the Pentagon last night for a press briefing. Defense Secretary Donald Rumsfeld said the Pentagon will be open for business today. Rumsfeld, whose offices reportedly are on the opposite side of the building from the crash site, said it was too early to estimate how many people were injured or killed in the attack. Published reports estimate the death toll at the Pentagon as anywhere from 100 to 500 people.