Glass, De-Fanged

Kepping windows from turning lethal

Up to 85 percent of injuries in bomb attacks are caused by flying glass--"knives and daggers," in the words of blast engineer Tod Rittenhouse. But thanks to commercial pressure for views and a graceful exterior, the Freedom Tower's skin will be mostly glass. Designers will use safety glass, but have not provided details. There are two ways to pacify glass: tinker with it chemically or keep it from traveling.