Timeline of attacks on US (as of 0115 GMT Wednesday)
( 2001-09-12 10:50 ) (7 )

The following is a detailed timeline of how the deadly terror attacks in New York and Washington unfolded on Tuesday:

8:56 am (1256 GMT) - An airliner smashes into one of the towers of the World Trade Center in New York, leaving a giant hole in the building's facade. Thick smoke trails into the sky from the tower's upper floors.

9:14 am (1314 GMT) - A second plane hits the second of the two World Trade Center towers, sparking a massive explosion.

9:40 am (1340 GMT) - US President George W. Bush, in Sarasota, Florida, calls the blasts "an apparent terrorist attack". He orders "a full-scale investigation to hunt down and to find those folks who committed these acts" and says he will immediately return to Washington.

9:50 am (1350 GMT) - In Washington, the White House is evacuated, shortly after the evacuation of the Pentagon (US Defense Department) in suburban Washington.

9:53 am (1353 GMT) - A plane smashes into the Pentagon building.

10:00 am (1400 GMT) - US officials at the Federal Aviation Administration (FAA) order the cancellation of all commercial flights in the United States.

10:05 am (1405 GMT) - One of the World Trade Center's two towers collapses following an explosion in a huge cloud of smoke and dust.

10:28 am (1428 GMT) - The second tower of the World Trade Center collapses like a house of cards, sending tons of debris into the surrounding streets. A huge cloud of dust blankets lower Manhattan.

10:42 am (1442 GMT) - US Secretary of State Colin Powell, in the Peruvian capital Lima, breaks off his trip to return to Washington.

10:50 am (1450 GMT) - United Airlines announces that one of the planes that hit the World Trade Center was one of its Boeing 737s.

11:17 am (1517 GMT) - New York City Mayor Rudolph Giuliani asks all New Yorkers to evacuate the southern tip of Manhattan.

11:34 am (1534 GMT) - A United Airlines Boeing 757 travelling from Newark to San Francisco crashes in western Pennsylvania, between New York and Washington.

11:38 am (1538 GMT) - American Airlines announces it has lost contact with two of its aircraft, carrying a total of 156 people.

11:53 am (1553 GMT) - Rail traffic is suspended between Boston and Washington.

12:50 pm (1650 GMT) - New York Mayor Rudolph Guiliani says he has called out the National Guard to help rescue efforts in the city.

13:30 pm (1730 GMT) - US President George W. Bush, who has travelled to Louisiana from Florida, says US armed forces are on maximum alert and vows to "hunt down and punish" those responsible.

13:50 pm (1750 GMT) - The mayor of Washington, Anthony Williams, declares an indefinite state of emergency in the federal capital.

14:00 pm (1800 GMT) - The Securities and Exchange Commission announces that financial markets will remain closed for the rest of the day.

15:20 pm (1920 GMT) - UN Secretary-General Kofi Annan says he "utterly condemns" the attacks.

15:35 pm (1935 GMT) - A top US official, who asks not to be named, says that the alleged terrorist mastermind Osama bin Laden is suspected of being behind the attacks.

15:36 pm (1936 GMT) - President Bush arrives at a base in the midwestern state of Nebraska to consult with top security officials.

16:54 pm (2054 GMT) - Mayor Guiliani says that the death toll of the attacks on the World Trade Center will not be known for at least a day, but that it will be "more than any of us can bear".

17:25 pm (2125 GMT) - A third building attached to the World Trade Center, 47 floors high, collapses in the wake of the disaster.

20:35 PM (0034 GMT Wednesday) - President Bush, in a televised address, says thousands have died in the terrorist attacks and that Washington will make no distinction between the terrorists and those who harbour them. The federal government will operate as normal Wednesday, he added.