Here is a timeline for Sept. 11, 2001, when commercial airliners crashed into the New York World Trade Center twin towers, the Pentagon and, after passengers mounted a counterattack, a Pennsylvania field.

Nearly 3,000 people were killed, including more than 2,600 at the World Trade Center, 125 at the Pentagon, and 265 on the four planes.

THE HIJACKINGS

American Airlines Flight 11

0759 EDT: American Airlines 11 departs from Boston for Los Angeles

0814: The flight has its last routine communication with the ground

0819: A flight attendant calls the airline’s reservation office in North Carolina via an airphone and reports an emergency

0841: A duty manager in American Airlines’ operations center in Fort Worth, Texas, is told air traffic controllers have declared the flight a hijacking and think the plane is headed toward New York’s John F. Kennedy International Airport

0844: North Carolina airline employee loses phone contact with the flight attendant. Another flight attendant in a phone call to American’s office in Boston says: “Something is wrong. We are in a rapid descent.” Asked to look out a window to try and determine where they were, flight attendant says: “We are flying way too low.” Seconds later she says, “Oh my God, we are way too low.”

0846: Flight 11 crashes into the World Trade Center’s North Tower

1028: North Tower collapses

United Airlines Flight 175

0758: United Airlines 175 departs from Boston for Los Angeles

0842: The flight reports a “suspicious transmission” overheard from another plane (American Airlines 11). It is the flight’s last communication with the ground

0852: A flight attendant calls the airline’s San Francisco office and reports the plane has been hijacked, both pilots killed, a flight attendant stabbed and hijackers probably flying the plane

0858: The flight takes a heading toward New York City

0903: The plane strikes the World Trade Center’s South Tower

0958: South Tower collapses in 10 seconds

American Airlines Flight 77

0810: American Airlines 77 departs from Dulles for Los Angeles

0854: Flight deviates from assigned course. Two minutes later transponder is turned off

0900: An American Airlines executive learns communications have been lost with flight, making it American’s second plane in trouble. All American Airlines flights in Northeast that have not yet taken off are ordered to remain on the ground. American makes the ground stop nationwide after learning a United Airlines plane is missing

0929: Flight 77 autopilot disengaged

0934: Ronald Reagan Washington National Airport advises U.S. Secret Service of unknown aircraft heading in direction of the White House. Plane makes a 330-degree turn and points toward Pentagon and downtown Washington

0937: Flight 77 crashes into the Pentagon

United Airlines Flight 93

0842: United Airlines 93 departs from Newark for San Francisco

0928: Flight 93 suddenly drops 700 feet (210 meters). Eleven seconds into the descent air traffic control in Cleveland receives the first of two radio transmissions; captain or first officer is heard declaring, “Mayday”

0958: Flight 93 passenger assault on hijackers begins

1002: Flight 93 plows into field in Shanksville, Pennsylvania

Federal Aviation Administration acts

0906: FAA stops departures of all flights bound to or through airspace of airports controlled by New York air traffic control and adjacent control centers

0908: FAA halts takeoff of all civilian planes nationwide

0945: FAA orders all civilian aircraft to land at nearest airport as soon as possible; 4,546 flights were airborne

THE PRESIDENT

0905: President George W. Bush is seated in a classroom in Sarasota, Florida, when his chief of staff whispers to him, “A second plane hit the second tower. America is under attack.” Bush remains in the classroom about five to seven minutes

0935: President’s motorcade departs, arriving at airport between 0942 and 0945

0954: Air Force One departs without any fixed destination and lands at Barksdale Air Force Base in Louisiana; soldiers encircle the plane before Bush descends. Bush is flown to Washington on a backup Air Force jet