Oops. Someone goofed. Bad day for the UP in Milwaukee, WI. There are numerous stories about this on the 'Net today. One example: http://www.jsonline.com/news/traffi...hit-by-train-cargo-b99232275z1-252006611.html
If you follow through the links and click on the small photo of the bridge damage, there are several impressive photos of the damage. The train really gave it a lick!
The "cargo" appears to be an "ArrowEdge" aerodynamic device that is supposed to improve the airflow around the head end of a double-stack container train. http://www.uprr.com/newsinfo/releases/environment/2013/0903_arrowedge.shtml It also appears to have been going "backwards" (blunt end first) when it hit the bridge. Oops.