Wednesday, 12 September, 2001, 01:26 GMT 02:26 UK
Thousands dead in 'evil' attacks
[Collapse of World Trade Center]
New York is paralysed and in a state of confusion
A grim-faced President Bush has mourned the deaths of thousands of Americans in the country's worst ever terrorist attack, vowing to find those responsible.
"Thousands of lives were suddenly ended by evil, despicable acts of terror," Mr Bush told the nation on television.
The World Trade Center in New York was destroyed and the Pentagon in Washington seriously damaged when hijacked airliners slammed into them on Tuesday.
[People flee the scene]
"Today our way of life, our very freedom came under attack in a series of deliberate and deadly terrorist acts," Mr Bush said.
He warned the US would make "no distinction between the terrorists who committed the attacks and those who harbour them".
The full resources of the US intelligence community and law enforcement agencies were searching for those who organised the attacks, Mr Bush said.
These acts shatter steel, but cannot shatter the steel of American resolve
Thousands are feared to have died inside the buildings and about 260 more are presumed to have perished on board the planes.
US officials voiced suspicions that the Saudi dissident and Islamic militant Osama bin Laden - who is based in Afghanistan - may have been responsible for the attacks.
New York remains in a state of intense fear and confusion, made worse by a thick fog of ash, fumes and debris from the ruins of the World Trade Center.
Huge explosions rocked the Trade Center as horrified onlookers watched two passenger jets plunge into its towers.
Panicking office workers jumped from windows in the skyscraper as it collapsed during attempts to evacuate the building.
Another nearby building, Salomon Brothers 7, collapsed several hours after the original catastrophe.
Mr Bush said the pictures of the attacks "filled us with disbelief, terrible sadness and a quiet, unyielding anger".
"These acts were intended to frighten us, but they have failed. Terrorist acts can shake the foundations or our biggest buildings but cannot touch the foundation of America."
In a series of spectacular blows:
* Two hijacked passenger airliners plunge into the twin towers of the World Trade Center, the subsequent explosions and fires causing the buildings to collapse
* The Pentagon is partly destroyed by another hijacked plane which crashes into it shortly after the New York attacks, setting it ablaze
* Unexplained explosions are reported near the State Department and Congress buildings in Washington
Another hijacked passenger jet - a United Airlines 757 - crashes in Pennsylvania, south-east of Pittsburgh, with all 45 people on board feared dead.
The plane's intended target was believed to be the Maryland presidential retreat, Camp David.
Government buildings including White House evacuated
Lower Manhattan evacuated and National Guard brought in
All commercial flights to and from US suspended until noon Wednesday (1600 GMT)
Warplanes ordered to attack any suspicious aircraft flying over US
Seven US warships sailed to New York, two aircraft-carriers to help in rescue efforts
The attacks have caused chaos on world stock markets. Trading has been suspended in New York and markets will remain closed on Wednesday. Share prices on European exchanges plummeted.
New York panic
United Airlines confirmed that two of its planes had crashed with a total of 110 people on board - one in Pennsylvania and the other in New York.
American Airlines said it owned the other two planes lost, which were carrying 156 passengers altogether.
New York's Mayor, Rudolph Giuliani, said a "tremendous" number of lives had been lost in the city.
About half of the 400 firefighters sent to the scene initially are now presumed dead, and New York police reported that 78 of their officers were missing.
Dr Steven Stern at St Vincent's Hospital in the Greenwich Village area of lower Manhattan said: "Hundreds of people are burned from head to toe".
Appeals have been issued for supplies of blood to help treat the injured.
In Washington, the Pentagon - the heart of the US military establishment - suffered a direct hit from another hijacked passenger jet.
Part of the five-sided structure collapsed and secondary explosions were reported as huge clouds of smoke rose from the wreckage.
[Smoke billows from the Pentagon]
Pentagon spokesman Glenn Flood said there were "extensive casualties and an unknown number of fatalities".
But US Defence Secretary Donald Rumsfeld later said "the Pentagon is functioning - it will be in business tomorrow".
World leaders have reacted with shock and outrage to news of the devastating attacks.
Among those sending messages of condolence were President Vladimir Putin of Russia, UK Prime Minister Tony Blair and French Prime Minister Lionel Jospin.
However, some Palestinians and other Arabs have been celebrating the attack on the United States - seen by them as Israel's main sponsor.