Pentagon inage shows interesting 'feature'!?!

Pentagon - Black, Upside Down "U" Shaped something or other!

Anybody else see an upside down "U" shaped black, sooty marking/signature, as seen from this IKONOS satellite image taken on 12 Sept. 01 by the US Govt? Web link:

go to second row of images, second image from left (9/12/01 date)