6:45 am: Mohamed Atta and Abdulaziz al-Omari arrive at Boston's Logan Airport.
7:35 am: Atta and al-Omari board American Airlines Flight 11, a Boeing 767 bound for Los Angeles.
7:40 am: Three additional plotters board Flight 11.
7:59 am: AA Flight 11 departs 14 minutes late from Logan.
8:14 am: United Airlines Flight 175, a Boeing 767 carrying 56 passengers and nine crew members, departs from Boston for Los Angeles. Five hijackers are aboard.
8:19 am: A flight attendant on Flight 11 alerts American Airlines, "The cockpit is not answering, somebody's stabbed in business class -- and I think there's mace -- that we can't breathe. I don't know, I think we're getting hijacked."
8:20 am: American Airlines Flight 77, a Boeing 757 with 58 passengers and six crew members, departs from Washington Dulles International Airport for Los Angeles. Five hijackers are aboard.
8:24 am: A radio transmission comes from Flight 11: "We have some planes. Just stay quiet, and you'll be okay. We are returning to the airport." (It is believed Atta mistakenly held a button directing his voice to radio rather than to the plane's cabin as he intended.)
8:26 am: Flight 11 makes a 100-degree turn to the south heading toward New York City.
8:34 am: The Air National Guard is alerted to the hijacking of Flight 11. Two F15 pilots begin to suit up.
8:38 am: Authorities request military help to intercept the jetliner.
8:42 am: United Airlines Flight 93 takes off from Newark Airport 40 minutes late with 37 passengers and seven crew members bound for San Francisco, following. Four hijackers are aboard. Its flight path initially takes it close to the World Trade Center before moving away westwards.
8:46 am: Two F-15 fighter jets are ordered to scramble from Otis Air National Guard Base in Massachusetts to intercept Flight 11.
8:46 am: Going roughly 466 miles per hour, Flight 11 crashes into the north face of One World Trade Center, between floors 93 and 99.
8:49 am: CNN breaks into a commercial to become the first national outlet reporting the crash.
8:51 am: A flight controller at the FAA's New York Center notices that Flight 175 had changed its transponder code twice four minutes earlier; he tries to contact the flight.
8:52 am: Lee Hanson receives a phone call from his son Peter, a passenger on United 175, who says "I think they've taken over the cockpit. An attendant has been stabbed -- and someone else up front may have been killed. The plane is making strange moves. Call United Airlines. Tell them it's Flight 175, Boston to LA." A flight attendant aboard calls a United Airlines office in San Francisco, reporting that the flight had been hijacked, both pilots had been killed, a flight attendant had been stabbed, and the hijackers were probably flying the plane.
8:54 am: Flight 77 deviates from its assigned course, turning south over Ohio.
8:55 am: Announcements are made over the building-wide PA system by officials in the still-undamaged south tower of the World Trade Center, reporting that the building is "secure" and that people should return to their offices.
8:55 am: President George W. Bush, who is visiting Emma E. Booker Elementary School in Sarasota, Florida, is told that a small twin-engine plane has crashed into the World Trade Center.
8:56 am: The transponder on Flight 77 is turned off. Radar contact with the aircraft is lost. The plane turns east and travels undetected for 36 minutes toward Washington, D.C.
8:58 am: Flight 175 turns toward New York City.
9:02 am: The Fire Department orders an evacuation of the World Trade Center.
9:03 am: Flight 175 crashes into the south face of Two World Trade Center, between floors 77 and 85.
9:04 am: The FAA stops all departures from airports in New England and eastern New York State.
9:05 am: As President Bush is about to begin reading The Pet Goat aloud to students, his chief of staff, Andrew Card, interrupts to whisper to the president, "A second plane hit the second tower. America is under attack."
9:06 am: The FAA bans takeoffs of all flights bound to or through the airspace of New York Center from airports in that Center and the three adjacent Centers - Boston, Cleveland, and Washington.
9:08 am: The FAA bans all takeoffs nationwide for flights going to or through New York airspace.
9:17 am: The FAA closes down all New York City-area airports.
9:21 am: All bridges and tunnels into Manhattan are closed.
9:26 am: The FAA bans takeoffs of all civilian aircraft regardless of destination.
9:28 am: Hijackers storm the cockpit on Flight 93 and take over the flight.
9:29 am: President Bush makes his first public statements about the attacks, in front of an audience of about 200 teachers and students at the elementary school. He states that he will be going back to Washington, that "We've had a national tragedy", and leads a moment of silence. No one in the President's traveling party has any information during this time that other aircraft were hijacked or missing.
9:33 am: Reagan National Airport tells the Secret Service that "an aircraft [is] coming at you and not talking with us," referring to Flight 77. The White House is about to be evacuated when it receives a report that Flight 77 has turned and is approaching Reagan International Airport.
9:35 am: Flight 93 reverses direction over Ohio and starts flying eastwards.
9:35 am: Based on a report that Flight 77 had turned again and was circling back toward the District of Columbia, the Secret Service orders the immediate evacuation of Vice President Dick Cheney from the White House.
9:38 am: Flight 77 crashes into the western side of the Pentagon. All 64 people on board are killed, as are 125 Pentagon personnel.
9:43 am: The White House and the Capitol are evacuated and closed.
9:45 am: United States airspace is shut down. No civilian aircraft are allowed to take off, and all aircraft in flight are ordered to land at the nearest airport as soon as possible. All international flights headed for the U.S. are redirected to Canada and Mexico.
9:57 am: Passengers revolt on Flight 93.
9:57 am: President Bush leaves Sarasota, Florida, on Air Force One. The plane reaches cruising altitude and circles for approximately 40 minutes while the destination of the plane is discussed.
9:59 am: The South Tower of the World Trade Center begins to collapse.
10:03 am: United Airlines Flight 93 is crashed by its hijackers 80 miles southeast of Pittsburgh before passengers succeed in breaching the cockpit door.
10:10 am: Vice President Cheney, unaware that Flight 93 has crashed, authorizes fighter aircraft to engage the inbound plane.
10:20 am: President Bush, aboard Air Force One, tells Vice President Cheney that he has authorized a shootdown of aircraft if necessary.
10:28 am: The North Tower of the World Trade Center begins to collapse.
10:50 am: Five stories of part of the Pentagon collapse due to the fire.
12:39 pm: On CNN, Senator John McCain characterizes attack as an "act of war."
5:20 pm: 7 World Trade Center, a 47-story building that had sustained damage from falling debris and widespread fires, collapses. The building, which contained New York City's emergency operations center, had been evacuated and there are no injuries or deaths as a result of the collapse.
7:24 pm: Members of Congress join on the steps of the Capitol and sing "God Bless America."
8:30 pm: President Bush addresses the nation from the White House. He says, "Today, our fellow citizens, our way of life, our very freedom came under attack in a series of deliberate and deadly terrorist acts. The search is underway for those who are behind these evil acts...we will make no distinction between the terrorists who committed these acts and those who harbor them."