I found a great website ( http://www.fold3.com/ ) and found a photograph of the 9th Air Force bombing the Seine River highway bridge in Mantes-Gassicourt, 20 miles west of Paris. The bridge was bombed in June of 1944. During the crossing of the Seine in August 1944, the 157th Combat Engineer Battalion built their bailey bridge (supported by barges) just above (north I believe) from this bridge. The cathedral (above and to the right of the bombing) is visible in a photograph I have of the 157th Bridge and in looking at the other photographs and current aerials of the city, you can tell exactly where the Bailey went across.
I know it has been said many times before, but war is a funny thing. We blow this bridge up to slow them down and then have to build another bridge in the same place to speed ourselves up. This bridge and site is most interesting for me because this is where my Granddad was shot through the leg and temporarily taken back to England. If this bridge was not blown up in June, he would not have gotten shot in August. Then again, they would have had a different job to do and things may have been different for the worse.