One person died and two others were injured early Saturday morning in a collision between an ambulance and semi-trailer on Interstate 29 a mile south of Jefferson.
The South Dakota Highway Patrol says a Midwest Ambulance based out of Sioux City was southbound on I-29 around 3:30am when the driver lost control.
The ambulance crossed both lanes, went across the median into the northbound lanes and struck the back end of the semi-truck and trailer.
The impact caused the semi-truck and trailer to roll onto its passenger side.
A 29-year-old female passenger in the ambulance was not wearing a seat belt and was thrown from the vehicle.
She was pronounced dead at the scene.
The 22-year-old male ambulance driver, who was wearing a seat belt, suffered non-life threatening injuries and was taken to a Sioux City hospital.
The 62-year-old male driver of the semi-truck also was wearing a seat belt and sustained minor injuries.
He was not hospitalized.
The accident closed Interstate 29 in that area for about eight hours, opening again at 11:20 a.m.
The state patrol has not released the names of those involved.