8:46 AM – Flight 11 crashes into the World Trade Center’s North Tower. All passengers aboard are instantly killed, and employees of the WTC are trapped above the 91st floor.
9:03 AM – Flight 175 crashes into the WTC’s South Tower. All passengers aboard are killed instantly and so are an unknown number of people in the tower.
9:28 AM – Hijackers attack on Flight 93.
9:37 AM – Flight 77 crashes into the Pentagon. All passengers aboard are instantly killed and so are 125 civilian and military personnel in the building.
9:45 AM – US airspace is shut down under Operation Yellow Ribbon. All civilian aircraft are ordered to land at the nearest airport.
9:59 AM – The South Tower of the World Trade Center collapses.
10:02 AM – Flight 93 plows into an empty field in Shanksville, Pennsylvania. Although its ultimate target is unknown, it was likely heading for either the White House or the US Capitol.
10:28 AM – The North Tower of the World Trade Center collapses.
5:30 PM – Building 7 of the World Trade Center collapses.
8:30 PM – President Bush addresses the nation.