MADISON, Wis. -- Six people were injured and Interstate 90 was congested for hours on Sunday after two separate crashes.

Traffic was tied up as emergency crews worked to clear crashes on both sides of the highway.

The incident happened at mile marker 150, near Stoughton, just before 4 p.m.

A crash happening in the westbound lanes injured five people, according to the Wisconsin State Patrol.

According to Wisconsin State Patrol, an 18-year-old Illinois woman lost control of her Chevy Tahoe and she overcorrected and ended up rolling into the median. Two passengers were ejected.

An inattentive driver in the eastbound lanes failed to slow down, causing a chain-reaction crash, injuring one person and snarling traffic in that direction.

MedFlight was called for some of the victims.

According to investigators, at least two of the four passengers weren't wearing their seat belts.

One woman, who had been wearing a seat belt, suffered life-threatening injuries.

All six people involved were taken to University of Wisconsin Hospital for treatment.

Authorities said that they don't believe alcohol was a factor in the crash.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.