Prepare for delays, San Antonio drivers. A major crash has partially shut down a highway that leads into the city on Thursday, July 16. It’s unclear what caused the crash, but torrential rain fell across the region overnight.

The crash occurred in the eastbound lanes of U.S. 90 around 7:24 a.m., and commuters are still experiencing delays, according to the traffic monitoring site Sig Alert. All lanes between Montgomery Road/John D. Ryan Boulevard and Loop 1604 are closed on the Far Westside. The route leads into San Antonio from Castroville.

Travelers are being directed to exit to the frontage road and are being warned of an expected hour-long delay. Traffic is backed up to State Highway 211 near Masterson Road and Texas Research Parkway, according to the SigAlert report.

Most cars in the area are at a complete stop. Those that are moving are traveling between 1 and 19 mph. Currently, there is no word on when the lanes will reopen or whether anyone was injured in the crash.

Make sure to visit the MySA traffic page for the latest transportation news, including traffic delays and construction projects around San Antonio.

This is a developing story. Check back for updates.