<In the grisly accounting of a jetliner crash, it comes down to pounds: The people on Flight 93 weighed a total of about 7,500 pounds. Miller supervised an intensive effort to gather their remains, some flung hundreds of yards. In the end, just 600 pounds of remains were collected; of these, 250 pounds could be identified by DNA testing and returned to the families of the passengers and crew.

It really isn't so hard to understand why so little was left of those bodies. According to this source, the human body is 70% water. Most of their bodies evaporated in the heat of the impact and fire. Using the 7,500 pound body mass estimate and removing the 70% that was water, you'd be left with 2,250 pounds of solid mass. However, much of that probably burned, too.

Years ago, an Air Force pilot told me that all of them had to have their footprints taken before beginning flight training. The reason was both morbid but logical - in most high speed crashes, about the biggest body part recovered is a boot with the foot still inside. Before DNA testing, that was one of the most reliable means for identifying what remained of the bodies. There certainly wasn't enough for fingerprints and rarely enough to use dental records, but they could often find a foot...