(all times are Eastern Daylight Savings Time)  

8:45 a.m. :

An American Airlines Boeing 767 jet (Flight 11 from Boston to Los Angeles , with 81 passengers and 11 crew aboard) crashes into the north tower of the World Trade Center . 

9:03 a.m. :

A second hijacked airliner, (United Airlines Flight 175 from Boston ) crashes into the south tower of the World Trade Center and explodes. Both buildings are on fire.

9:30 a.m. :

President Bush says that the country has suffered an "apparent terrorist attack."

9:40 a.m. :

For the first time in U.S. history, the FAA halts air traffic nationwide.

9:43 a.m. :

American Airlines Flight 77 (a Boeing 757 en route from Washington 's Dulles International Airport to Los Angeles with 58 passengers and six crew members aboard) crashes into the Pentagon.

9:45 a.m. :

The White House evacuates.

10:05 a.m. :

The south tower of the World Trade Center collapses.

10:10 a.m. :

A portion of the Pentagon collapses.

10:10 a.m. :

United Airlines Flight 93 (en route from Newark , New Jersey , to San Francisco , California ) crashes in Somerset County , Pennsylvania , southeast of Pittsburgh .

10:13 a.m. :

The United Nations building evacuates.

10:22 a.m. :

In Washington , the State and Justice departments are evacuated, along with the World Bank.

10:24 a.m. :

The FAA announces that all inbound transatlantic flights are diverted to Canada .

10:28 a.m. :

The World Trade Center 's north tower collapses.

10:45 a.m. :

All federal office buildings in Washington are evacuated.

10.46 a.m. :

U.S. Secretary of State Colin Powell cuts short his trip to Latin America to return to the United States .

10:54 a.m. :

Israel evacuates all diplomatic missions.

10:57 a.m. :

All New York state government offices are closed.

12:04 p.m. :

Los Angeles International Airport , the destination of three of the crashed airplanes, is evacuated.

12:15 p.m. :

San Francisco International Airport is evacuated and shut down. The airport was the destination of United Airlines Flight 93, which crashed in Pennsylvania .

1:04 p.m. :

President Bush speaks to the country from Barksdale Air Force Base in Louisiana :  “…Make no mistake, the United States will hunt down and punish those responsible for these cowardly acts”…

1:27 p.m. :

The city of Washington declares a state of emergency.

1:44 p.m. :

The Pentagon dispatches five warships and two aircraft carriers (the USS George Washington and the USS John F. Kennedy) to protect the East Coast from further attack.

4 p.m. :

CNN reports that U.S. officials say there are "good indications" that Saudi militant Osama bin Laden, suspected of coordinating the bombings of two U.S. embassies in 1998, is involved in the attacks, based on "new and specific" information developed since the attacks.

4:10 p.m. :

Building 7 of the World Trade Center is on fire.

5:20 p.m. :

Building 7 of the World Trade Center complex collapses.

6:54 p.m. :

President Bush returns to the White House. 

8:30 p.m. :

President Bush addresses the nation, saying …“thousands of lives were suddenly ended by evil” …”These acts shattered steel, but they cannot dent the steel of American resolve…”   The President puts the world on notice by saying …”the U.S. government will make no distinction between the terrorists who committed the acts and those who harbor them”… He adds that government offices in Washington are reopening for essential personnel Tuesday night and for all workers Wednesday.

10:49 p.m. :

Attorney General Ashcroft reports to members of Congress that there were three to five hijackers on each plane armed only with knives.

(all times are U.S. Eastern Daylight Savings Time)