What Does It Mean?

Of the four 9/11 crashes, the Pentagon easily had the most airplane debris pieces photographed and in the public record.

Why?

Because a plane really crashed there and it was the most accessible site to photographers?

Or because the site was so accessible, the perps made sure plenty of aircraft debris was planted to promote the plane crash idea?

UPDATE: To clarify, for all four crashes we've been shown astonishingly little true plane debris from four huge aircraft. Just that relatively, we've seen more for the Pentagon hit.