Flagstaff, Arizona, turned into Willy Wonka’s chocolate factory Monday when a tanker truck spilled 3,500 gallons of it across Interstate 40.

The “river of chocolate” flowed onto the highway’s westbound lanes east of Flagstaff near the 211-mile marker, the state Department of Public Safety tweeted.

The tanker was transporting around 40,000 pounds of 120-degree liquid chocolate, officials said.

It was not immediately clear why the truck rolled over or when the mess was fully cleaned up.