Flooding in the Midwest Tuesday shut down portions of two interstates and threatened hundreds of homes, the Associated Press reports. At least 18 people have been killed. South of St. Louis, the Mississippi river, swollen after days of torrential rain, is expected to crest at record levels later this week.

From the AP:

On Tuesday the river spilled over the top of the levee at West Alton, Missouri, about 20 miles north of St Louis. Mayor William Richter ordered any of the town’s approximate 520 residents who had not already evacuated to get out of harm’s way.

Interstate 44 was closed near the central Missouri town of Rolla, and a section of Interstate 70 was shut down in southern Illinois. Hundreds of smaller roads and highways were also closed across the two states, and flood warnings were in effect.

On Tuesday, the Coast Guard shut down a five-mile stretch of the Mississippi near St. Louis, and a 3,700-person prison in Illinois was preparing for possible flooding. Wastewater plants across both states shut down, sending untreated sewage into the overflowing streams and rivers nearby.

Photo via AP Images. Contact the author of this post: brendan.oconnor@gawker.com.