DENVER (KDVR) — Police are investigating a single car rollover that seriously injured one person.

According to the Denver Police Department, officers were investigating a crash shortly before 3 a.m. at 56th Avenue and Worchester Street in the Montbello neighborhood. The intersection sits directly south of the Rocky Mountain Arsenal National Wildlife Refuge.

Investigators determined the crash involved only one motorist. According to officers, the driver lost control of the vehicle causing it to roll. The passenger inside the vehicle was seriously injured and transported to a local hospital.

The driver is now being held for investigation of vehicular assault and DUI.

According to the Colorado Department of Transportation, DUI crashes are all too common on Labor Day weekend.

“Labor Day weekend is one of our highest DUI arrest weekends of the year and so that means there are going to be a lot more people drinking and driving out there on the roadways,” Master Trooper Gary Cutler said.

In the last 10 years, there have been 78 fatalities over Labor Day weekend.