7:45 a.m. update
OLIVIA -- Authorities have identified the driver killed in an explosion Sunday morning. Brad M. Ripley, 44, of Mankato was the driver of a tractor-trailer that was hauling propane before it exploded outside Olivia, according to the Minnesota State Patrol.
The State Patrol said the tractor-trailer apparently rolled over as it turned from U.S. Highway 212, on the western edge of Olivia, to go north on U.S. Highway 71.
The truck then caught fire and exploded. The accident happened at 7:18 a.m. The Renville County Sheriff's Department and Olivia Police Department assisted the State Patrol at the scene.
Witnesses in Olivia reported hearing the thunder of the explosion and seeing flames. The blast was also felt throughout the surrounding area.
Debris was scattered across the highway and nearby field. The pavement was scorched, and a wide expanse of grass was charred on both sides of the road.
Traffic was detoured around the crash site for several hours.
The State Patrol said road conditions were dry at the time of the crash.