The bridge is in the water. The roadway surface of the bridge ended up just below the surface of the water.
The pictures at the link below show it...click on the pictures for larger view [Getty Images cannot be posted here].
Also please notice that the places where the bridge steel is bent or ripped apart apparently were already marked with orange paint before the collapse [to the left of the cars and in the upper left corner].
Looks like rust, not paint, to me.
You are seeing where the surface finish paint cracked off due to the stretching and deformation of the metal. You are seeing the primer layer underneath.
Could the paint over the primer have popped due to movement of the underlying steel? From the image, and without knowing if that orange was primer or added later, I can’t understand what the color patterns show us.
PS Thanks for an excellent about page with - the how to data about FR page format was very appreciated.
Good catch, I wonder what the most recent engineering rating on that bridge was from WADOT.