Quoting the local TV news channel: "The Corps of Engineers said a material failure caused damage to the dam’s upper miter gate. Demopolis Mayor Woody Collins said a chunk of concrete collapsed, creating significant damage after it fell."
Is this another example of aging transportation infrastructure failing because of deterioration and neglect? Not suggesting that's the case here, as I don't know that particular lock system. But this incident will cause lots of problems, and the inland waterways news has for years been full of stories about obsolete locks and dams being pushed past their design life.
"Less judgment than wit is more sail than ballast. Yet it must be confessed that wit give an edge to sense, and recommends it extremely." ~ William Penn