Most likely true, Greg. It's the same flood that took out an important Iowa River Bridge in Boone County during the floods. You can see it here: http://bridgehunter.com/ia/boone/77850/
Next time you go, get some pics of it. Even photos of a damaged bridge are better than no photos at all.
Visit Sept. 08 found road closed. North end of bridge sitting on abutment, South end washed to the East and twisted on it's side in a gravel bar. In general, bridge bent in a "u" plus twisted onto it's side. Lot's of timber debris washed into the side. Assume this is damage from spring floods, but possible earlier.