GRAND RAPIDS, Mich. (WOOD) — A woman was hospitalized in critical condition after being hit by a vehicle on a highway in Grand Rapids, according to Michigan State Police.

It happened around 11:15 a.m. Friday morning. A woman was southbound on US-131 when her vehicle slipped on an unknown “oily substance” and ran into a wall on the side of the highway near the Wealthy Street exit, MSP said in a tweet.

She then got out of her vehicle and was hit by another vehicle that was headed south. The woman was taken to the hospital, where she is in critical condition.

There is a hazmat team at the scene trying to figure out what the substance was. MSP is asking drivers to avoid the S-curve while crews clean up the substance.

The right lanes of US-131 were blocked for hours. All lanes reopened around 3:30 p.m.