Dan Barry The New York Times

After the roar, after the first ground-trembling collapse sent clouds of pulverized matter billowing through Lower Manhattan, a man paused from his hurried retreat to take in a world now coated with the dust of uncertain gray. For reasons he still cannot explain, he bent down, scooped some of this grayness into an envelope - and kept on moving.

After the roar, after the first ground-trembling collapse sent clouds of pulverized matter billowing through Lower Manhattan, a man paused from his hurried retreat to take in a world now coated with the dust of uncertain gray. For reasons he still cannot explain, he bent down, scooped some of this grayness into an envelope - and kept on moving.