I am noticing a common theme on a lot of the train wrecks I have been looking at this week . . . failed bridges. It appears that often a flood or other event can weaken a bridge, but not give any outward signs of damage, then when the train goes over, the weight of the train causes a collapse of the bridge. This picture was taken in 1902 in Maricopa County, Arizona. This must have been a terrible mess to clean up.