Bin Laden gives chilling account of Sept. 11

The U.S. government has released the long-awaited videotape of suspected terrorist Osama bin Laden talking about the Sept. 11 attacks with several other men.

According to the official translation bin Laden says the number of casualties were "calculated in advance." He said he was the most optimistic of all the planners in estimating the attack's success but even he did not predict the buildings' complete collapse.

"We calculated in advance the number of casualties from the enemy, who would be killed based on the position of the tower. We calculated that the floors that would be hit would be three or four floors. I was the most optimistic of them all. (...Inaudible...) due to my experience in this field, I was thinking that the fire from the gas in the plane would melt the iron structure of the building and collapse the area where the plane hit and all the floors above it only. This is all that we had hoped for," said bin Laden, according to the translation.

On the tape, bin Laden says he had advance notice that the attacks would happen on September 11 and he described listening to the radio for news that day.

"After a little while, they announced that another plane had hit the World Trade Center. The brothers who heard the news were overjoyed by it," he said.

Bin Laden says the hijackers were not told the details of their mission until just before they boarded the plane.

"The brothers, who conducted the operation, all they knew was that they have a martyrdom operation and we asked each of them to go to America but they didn't know anything about the operation, not even one letter. But they were trained and we did not reveal the operation to them until they are there and just before they boarded the planes," he said.

Bin Laden also said he told his followers there would be more destruction after the first plane hit the World Trade Center, and he identified Mohamed Atta as the man responsible for organizing the attacks.

On the grainy amateur video, bin Laden is smiling and appears relaxed. He is seen seated on the floor with spiritual adviser Ayman al-Zawahri and spokesman Abu Ghaith. Later he is shown eating bread.

The tape is 40 minutes long. The Pentagon says it was recorded in a guest house in Kandahar, Afghanistan. Officials say the tape was found at a house in Jalalabad, but they did not say how it got into American hands.

Secretary of Defense Donald Rumsfeld acknowledged Thursday that there were reports that bin Laden had left the country, but said the U.S. believes he is still in Afghanistan.

On Wednesday, the Christian Science Monitor quoted a senior al-Qaeda operative as saying bin Laden had fled to Pakistan more than a week ago.