3-D Duh

A computer simulation of the 2001 World Trade Center attacks supports a federal agency's findings that the initial impact from the hijacked airplanes stripped away crucial fireproofing material and that the weakened towers collapsed under their own weight.

The two-year Purdue University study, funded in part by the National Science Foundation, was the first to use 3-D animation to provide visual context to the attacks, said Christoph Hoffmann, a professor of computer science and one of the lead researchers on the project.

"One thing it does point out... is the absolute essential nature of fireproofing steel structures," Hoffmann told The Associated Press. "This is something that wasn't done originally in the World Trade Center when it was built. It wasn't code at that time."