By CBS3 Staff

GLOUCESTER COUNTY, N.J. (CBS) — Police in New Jersey are investigating after a truck driver was found dead in his tractor-trailer. The owner of the Empire Diner in Westville says the truck parked behind his restaurant on Thursday.

The diner owner thought the driver was just resting or delayed, but got worried Sunday and decided to knock on the windows.

When there was no response, the man called the police.

Download The New And Improved CBS Philly App!

“The truck was running, constantly running. The AC was working. I thought he was just getting rest because sometimes they have to because hey cannot be on the road too long,” Dervis Akturk, owner of the diner, said. “I was just thinking to myself too, it was Fourth of July weekend, where is he going to deliver? Everything is closed.”

The Westville police and Gloucester County Prosecutor’s office are investigating.