LEWISVILLE (CBSDFW.COM) – The driver of a tour bus was found dead by authorities after pulling over on the side of a highway in Lewisville.

Police responded to the call just before 2 p.m. in the southbound lanes of the Sam Rayburn Tollway near Denton Tap Road.

A Lewisville police spokesperson said the driver of the bus pulled over onto the left shoulder. When he was checked on by officers and paramedics, he was found dead.

There are no immediate signs of foul play. The identity of the driver has not been released.

The exact cause of the driver’s death is under investigation.