A serious crash is causing a major detour on Interstate 29 south of Sioux Falls.
Authorities say a semi was over-driving the conditions when it rear-ended a pickup pulling a small livestock trailer. That pushed the pickup into the ditch.
The drivers were both wearing their seat belts and are okay, but a passenger in the pickup was tossed from the vehicle. She has serious injuries; authorities say she wasn't wearing a seat belt.
The interstate had to be closed as the investigation took place. Authorities hope to have it reopened by 12:30 p.m.