Authorities on Monday identified the husband and wife who were killed in central Minnesota when their horse-drawn buggy was hit from behind on a rural road.

Robert A. Keppers, 72, and Mary J. Keppers, 66, both of Avon, died after the crash, which happened about 11:15 a.m. Sunday as they traveled along the shoulder of County Road 9 north of Avon, according to the Stearns County Sheriff’s Office.

Marc L. Knapp, 23, of Avon, was also driving north when he struck the single-horse buggy from behind, sending it into the ditch. Several people stopped to assist and help with resuscitation efforts, the Sheriff’s Office said, but the couple died at the scene. The horse also died.

A photo of the crash scene from the Sheriff’s Office shows an orange triangle on the back of the crumpled buggy, a sign used to alert motorists of a slow-moving vehicle ahead.

“It’s unusual to have somebody with their horse and buggy on a county road,” Chief Sheriff’s Deputy Jon Lentz said. “On township roads, it’s not that unusual.”

The State Patrol and Sheriff’s Office are investigating the crash and said Monday that there is no indication alcohol was involved and no one has been arrested.

In September, a motorist hit an Amish buggy in Fillmore County, killing a 21-year-old man; the 24-year-old driver in that case was drunk and was charged with four counts of criminal vehicular homicide.

Star Tribune staff writer Kelly Smith contributed to this report.