How Has Skyscraper Design Changed Since 9/11?

Aired: 9/6/2011 | 0:10:49 | Clip
The collapse of the Twin Towers served as a stark and stunning reminder to architects and engineers of the value of using concrete to protect skyscrapers from the ravages of fire. Miles O'Brien reports on how the design of skyscrapers has changed since 9/11. This report was produced in collaboration with the PBS program "NOVA."