In pictures: Terror strikes America

It will be remembered as the morning terror struck at the heart of America. The 110-storey World Trade Center was struck by two planes as horrified New Yorkers looked on.

A third plane struck the Pentagon in Washington, causing the evacuation of the military and intelligence building as it burned. Here are the tragic moments in pictures:

Smoke billowed out of the World Trade Center after the first plane hit it

Less than 18 minutes later, another plane closed in on the other tower

The plane seemed to swerve to hit the other tower

The second plane caused a massive explosion and fire on the second tower

The South Tower collapses in a cloud of debris and smoke

The collapse obscures much of downtown Manhattan

The collapse of the second tower, the West Tower, followed shortly afterwards

Terrified survivors try to flee, stumbling through a fog of smoke and shredded debris from the collapsed towers

Across the river from Manhattan, crowds watched the drama unfold in stunned silence

Shocked people at St Patrick's Cathedral watch the World Trade Center collapsing

Emergency services rushed to evacuate lower Manhattan and rescue casualties before the towers collapsed

Police, firefighters and paramedics were close to the towers when they collapsed

The Pentagon was also hit - by some sort of aircraft - minutes after the World Trade Center explosions

George Bush was told the news as he spoke to children in a Florida school

Smoke was visible across the whole of Manhattan island