APTOPIX Damaged Dam
Water flows through break in the wall of the Oroville Dam spillway, Thursday, Feb. 9, 2017, in Oroville, Calif. The torrent chewed up trees and soil alongside the concrete spillway before rejoining the main channel below. Engineers don't know what caused what state Department of Water Resources spokesman Eric See called a "massive" cave-in that is expected to keep growing until it reaches bedrock. (AP Photo/Rich Pedroncelli)
