Signal Hill police closed down a section of Willow Street between California and Myrtle avenues for over four hours early Friday morning after finding a dead driver behind the wheel of a car in the westbound lanes.

Police said they believe the man’s death was natural and that he died from an unspecified medical emergency.

Officers first found the parked car around 5:45 a.m. and quickly discovered the driver was unresponsive.

After administering CPR, officers called paramedics, who determined the man was dead at the scene, according to Signal Hill Police Department Sgt. Don Moreau.

The street section was closed down until 10 a.m., while officers waited for mortuary workers to arrive, Moreau said.