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.