A semi-truck rollover on Interstate 80 near Silver Creek Junction early Thursday morning left one person in critical condition and caused the closure of all westbound lanes for several hours.

The crash occurred around 5 a.m. near milepost 146, when the semi struck an elk, lost control, and overturned, according to the Utah Highway Patrol. The truck also collided with another vehicle during the incident.

According to KPCW, the driver of the car hit by the semi was critically injured, while the semi driver sustained minor injuries and was taken to the hospital.

The semi was carrying oil, prompting a hazmat response to contain the spill. All westbound lanes of I-80 were closed for several hours and reopened around 10:30 a.m.

Authorities have not yet released the names of those involved. The incident remains under investigation.