How many bridge collapses are caused by floods versus other kinds of failure? In the Northwest, we're pretty worried about the next big earthquake, whenever it

How many bridge collapses are caused by floods versus other kinds of failure? In the Northwest, we're pretty worried about the next big earthquake, whenever it happens. I also assume that bridges sometimes just fall down on their own due to corrosion, metal fatigue, low quality materials, improper construction, or uneven thermal expansion of various materials.