POCATELLO, Idaho (AP) — Authorities in southeast Idaho say fish being battered on rocks after going over a spillway resulted in a fish kill in the Snake River below American Falls Dam.

Idaho Power spokesman Brad Bowlin tells the Idaho State Journal that Idaho Power biologists determined the fish went over the spillway during an August storm. Bowlin says that during the storm, the power house at the dam stopped because some water entered the building. He says that resulted in water going over the spillways along with fish.

The newspaper reports that the fish are mostly large carp and suckers. The Idaho Department of Fish and Game three years ago designated the river below the dam as catch-and-release as a way to boost tourism in American Falls.