A 49-year-old Hudson Valley school bus driver was found dead in the back of his empty bus.

On Friday afternoon, a 49-year-old male school bus driver in Ulster County parked his Arthur F. Mulligan bus at its normal spot in the Town of Ulster and began checking the back of the bus for any potential sleeping children, a normal end of shift procedure.

“At this time the man had a medical issue, sat down in the back seat and died,” Ulster County Sheriff's Office Undersheriff Michael Freer told Hudson Valley Post.

A woman who works as a bus monitor with the 49-year-old got on the bus Monday morning, saw him deceased, and called 911.

“We did an investigation and did an autopsy,” Freer said. (He died of) natural causes.”

Freer later confirmed that it was a heart attack.

The driver’s name isn’t being released at this time. It’s known how long he worked for the bus company.