Here’s what’s causing record-breaking flooding in the Midwest

Torrential rains aren’t the only factor.

Hundreds of Iowa residents have needed rescue from record-setting flooding that has swamped parts of the state, covering buildings up to their rooftops, shutting down major roads, and disrupting basic services like electricity and drinking water.

Iowa Gov. Kim Reynolds said water in some areas rose above records from 1993, a flood many in the Midwest remember as the worst of their lives. The floods have hit parts of Iowa, South Dakota, Nebraska and Minnesota.

The water was so powerful that it pulled down a train bridge connecting North Sioux City, South Dakota, with Sioux City, Iowa. On the Blue Earth River in Minnesota, water forced its way around the Rapidan Dam and local officials warned of its possible failure.

The water is expected to be at its highest early this week — in some places it has already passed — and then the crest of the river will move south, eventually into the Missouri and Mississippi rivers.

“Businesses are shuttered, main streets have been impacted. Hospitals, nursing homes and other care facilities were evacuated,” Reynolds said at a news conference over the weekend, calling the expected damage “staggering.”

It’s hot, too, making dangerous conditions worse.

A look at why waters are so high in the Midwest: