Christopher Johnson, 57, killed, Bradley Hake, 49, Hubert Akers, 49, uninjured, after a 3-vehicle crash, including a tractor-trailer, on U.S. 98 near Lakeland, in Polk County.

Polk County Sheriff's deputies are investigating a three-vehicle traffic crash involving a semi-tractor-trailer, a pickup truck and a private ambulance that killed a Lakeland man on Thursday.

Around 12:40 p.m. officials say the semi-truck pulling a trailer was heading northbound on US 98 near Old Soldier Road in Lakeland when the driver of a pickup truck, 57-year-old Christopher Johnson of Lakeland, was heading southbound and, for unknown reasons, drifted across the centerline, striking the semi. The driver of the semi, 49-year-old Bradley Hake of Ocala, tried to avoid a collision with the pickup truck, but was unsuccessful. An ambulance belonging to American Medical Services also ran off the roadway to avoid the collision and struck the pickup truck.

The ambulance's driver, 43-year-old Hubert Akers of New Port Richey, responded to the pickup truck and determined that Johnson was deceased. He was the only occupant of the pickup truck.

Neither of the other drivers received injuries.

US 98 was shut down for most of the afternoon but has since re-opened to traffic.

All drivers were wearing seatbelts. Nether excessive speed nor impairment appear to be a factor. The investigation is ongoing.