(NewsNation) — A windstorm on an interstate in south-central Illinois on Monday led to numerous crashes that left at least six people dead, Illinois State Police said.

The crashes happened late Monday morning and involved 40 to 60 cars and multiple tractor-trailers, two of which caught fire, Illinois State Police Maj. Ryan Starrick said.

Starrick initially reported “multiple fatalities” and said more than 30 people were rushed to hospitals for their injuries.

In response to the windstorm and crashes, Illinois State Police shut down both south and northbound lanes of I-55 from milepost 63 to 80. The agency urged drivers to seek alternative routes.

Officials designated the Auburn Travel Center as a reunification point for drivers and their loved ones following the crash between Divernon and Farmersville.

“Visibility in the area is reported to be low due to blowing dust,” Illinois State Police said in a statement earlier Monday. “Traffic is urged to seek alternate routes. This investigation is in its infancy and there is no further information at this time.”

The National Weather Service St. Louis said a combination of newly plowed fields and gusty winds generated the dust storm, which caused reduced visibility in the immediate area.

Winds at the time were gusting between 35 mph (56 kph) and 45 mph (74 kph), the National Weather Service said.

“It’s very flat, very few trees,” meteorologist Chuck Schaffer said. “It’s been very dry across this area really for the last three weeks. The farmers are out there tilling their fields and planting. The top layer of soil is quite loose.”

Starrick said the storms have happened before on Illinois roads “where unfortunately you have excessively high winds” that blow the topsoil from fields.

I-55 is expected to be closed until Tuesday morning or afternoon.

The Associated Press contributed to this report.