A timeline of events on Sept. 11, 2001

How Sept. 11, 2001, unfolded:

8:00: The first of four planes bound for California, American Airlines Flight 11, leaves Logan International Airport in Boston with 92 people aboard.

8:14: United Airlines Flight 175 leaves Boston with 65 people.

8:21: American Airlines Flight 77 leaves Dulles International Airport in Reston, Va., with 64 people aboard.

8:35: The Federal Aviation Administration alerts the government that Flight 11 has been hijacked.

8:42: United Airlines Flight 93 leaves Newark International Airport with 45 people on board.

8:43: FAA sounds alert that Flight 175 was also hijacked.

8:44: Two F-15 fighters race from Cape Cod, Mass., to intercept the planes.

8:46: American Airlines Flight 11, carrying 20,000 gallons of fuel, crashes into the north tower of the World Trade Center, killing all aboard and destroying floors 90 through 100.

9:00: More than 200 firefighters from across New York City begin rescue operations at the trade center.

9:00: President George W. Bush arrives at Emma E. Booker Elementary School in Sarasota, Fla., to speak to children and teachers. White House Chief of Staff Andrew Card informs him that a plane crashed into the World Trade Center.

9:02: Cameras covering the crash at the north tower capture images of Flight 175 smashing into the World Trade Center’s south tower. It strikes between floors 78 and 87, resulting in a massive series of explosions.

9:05: Bush is informed that a second plane crashed into the World Trade Center.

9:08: All New York-area airports closed.

9:21: All bridges and tunnels in New York closed.

9:24: FAA says Flight 77 was also hijacked. Two fighter jets from Langley Air Force base in Virginia are sent to intercept the plane.

9:26: All non-military planes grounded. For the first time in history, all flights in the United States are canceled. All incoming transatlantic flights are diverted to Canada.

9:30: President Bush makes his first comments, stating “We have had a national tragedy.”

9:41: Flight 77 crashes into the Pentagon. Part of the building collapses.

9:45: White House evacuated.

9:48: U.S. Capitol evacuated.

9:50: South tower of World Trade Center collapses in a gigantic cloud of smoke, dust and debris that stretches into New Jersey.

9:52 (approx.): United Flight 93 passes a few miles south of Pittsburgh.

9:58: 911 operator in Somerset County receives a cell phone call from a Flight 93 passenger saying that they were being hijacked.

10:00: President puts nation’s military on highest alert.

10:00 a.m.: Flight 93 crashes in Shanksville, not far from Route 30 in Somerset County. It is later determined that several passengers on the plane likely overpowered the hijackers, preventing them from reaching their intended target.

10:28: World Trade Center’s north tower collapses, killing hundreds of firefighters and more than 1,000 workers and tourists.

11:18: American Airlines confirms two of its planes were hijacked and feared crashed.

12:15 p.m.: Canadian and Mexican borders closed.

1:27: State of emergency declared in Washington, D.C. All federal buildings evacuated.

1:44: Navy ships leave Norfolk, Va., Naval station to protect East Coast from further attack.

2:30 p.m.: Commercial air traffic postponed indefinitely.

4:01: Federal officials report “good indications” that Osama bin Laden, already suspected in bombing of USS Cole, is involved in attacks on America.

4:10: 7 World Trade Center, adjacent to the towers, reported to be engulfed in flames.

4:36: President Bush departs Offutt Air Force Base in Nebraska for Washington. While aboard Air Force One, he prepares a speech he intends to give the nation later that evening.

5:20: The 47-story 7 World Trade Center building collapses. Later, the North Bridge and St. Nicholas Church also collapsed. The Marriott Hotel, as well as 4, 5 and 6 World Trade Center were partially collapsed.

5:30: U.S. official confirms Flight 93 could have been headed for either Camp David in Maryland, the White House or U.S. Capitol building.

6:55: Bush arrives at the White House after landing at Andrews Air Force Base in Maryland escorted by fighter jets. He immediately plans for his speech, scheduled for 8:30 p.m. Eastern Time.

7:45: New York City fire and police departments announce they have a number of members unaccounted for.

8:30: President Bush delivers his speech to the nation, stating “thousands of lives were suddenly ended by evil.” In asking for prayer he adds, “These acts shattered steel, but they cannot dent the steel of American resolve.”