Iowa is using a Blackhawk helicopter to drop 1,000-pound sandbags on a levee leak that threatens to flood a community in the southwestern part of the state. Gen. Derek Hill of the Iowa Department of Homeland Security says sandbags were being dropped Sunday on a leak in a levee in Atchison County, Mo. He says it was too dangerous to use ground crews for the work.

The U.S. Army Corps of Engineers reported Sunday morning there was a breach in a Missouri River levee that could flood Hamburg, Iowa. The city is about five miles north of the leak, and Hill says the land in that area is flat and the leaking water is expected to flow back into Hamburg.

The leak has forced the evacuation of 600 Hamburg residents.