DENVER (KDVR) — Larry Hagen couldn’t wait to get his favorite combo meal at McDonald’s, but when he pulled into the drive-thru line, he got a shock.

“They were washing some type of sludge off the parking lot,” Hagen said.

Desiree Eke told FOX31 the pavement at the McDonald’s, located at Wadsworth Boulevard and Crestline Avenue, was slippery.

“I actually was driving the Jeep through and slipped,” Eke said.

Customers rolled down their windows and noticed a disturbing smell.

“It was totally disgusting,” Eke said.

Eke and Hagen told FOX31 they quickly headed to local car washes to get rid of the residue stuck to the bottom of their cars and in the wheel wells.

“That sludge fell off on the garage floor, so I drove straight to the car wash,” Hagen said.

The Denver Department of Public Health and Environment told the Problem Solvers inspectors visited the property and found a grease spill had taken place but did not affect any food inside the restaurant.

The staff cleaned up the grease immediately. A follow-up inspection will be conducted.