TULSA, Oklahoma - Tulsa Police are looking for the vehicle that left behind a mysterious spill that caused a rollover crash on Highway 169 Tuesday evening.

Officers say the spill caused a van to go out of control and rollover in the northbound lanes just north of the Creek Turnpike at about 6:45 p.m. Police said the two people in the van weren't hurt. 

Police believe a truck spilled the greasy substance from 91st Street to 81st Street. 

The Tulsa Fire Department Hazardous Materials team was sent to clean up the fluid, which will take some time. The spill is in the center lane of Highway 169.