City of Dust

6. Building a science

The gasping firefighters who reluctantly dragged themselves away from the pile to see Drs. Kerry Kelly and David Prezant had responded immediately, and bravely, to the largest disaster they had ever experienced. On the enormous mound of twisted steel, shrouded in the choking smoke and ash of super-hot fires below ground—standing like sentries at the gates of hell—they became symbols of the city’s resolve. But in truth, with their buckets and pickaxes, they were no match for the devastation left by the terrorists. If there was anybody left to rescue, the firefighters needed big help reaching them.

The help had started to arrive almost at once. Within days of the attack, an army of construction workers in hardhats and overalls ...