The operator of a tractor-trailer fell asleep while driving on Interstate 81, state police at the Schuylkill Haven barracks said.

Police said the incident occurred at 4:26 a.m. on Nov. 27 on Interstate 81 in Ryan Township.

Rafael Santana, 26, of Harrisburg, was driving a 2013 Freightliner when he fell asleep and the rig drifted toward the right shoulder of the road, police said.

When Santana attempted to correct the rig, the vehicle overturned onto its passenger side, police said. It slid off the right shoulder of the highway and came to an uncontrolled stop in a grassy area.

Santana, who was uninjured, was cited for careless driving, according to police.

The rig was towed from the scene.