A motorist from the Twin Cities area left his broken-down recreational vehicle along a southern Iowa interstate to chase after his dog on Christmas night and was fatally run over while his wife waited in the vehicle, authorities said Thursday.

Lawrence Anderson, 74, of Marine on St. Croix, was struck about 10:30 p.m. by a sport-utility vehicle on southbound Interstate 35 near St. Charles, according to the Iowa State Patrol.

Anderson had pulled the couple’s RV onto the left shoulder because of mechanical trouble and summoned help, said the patrol’s Christal Hills.

Anderson then got out and was in the road “chasing a dog that had gotten away from him,” the patrol report read.

A southbound SUV hit Anderson in the left lane, throwing him into the median against the cable barrier.

The SUV driver, Shelton Short, 34, of Osceola, Iowa, “did not see the pedestrian and was unable to avoid [the] collision,” according to the patrol report. Short was not injured.

The dog, a bichon frise named Toby, was recovered and taken to a nearby shelter, said Carol Clark of the Kiya Koda Humane Society in Indianola, Iowa.

Toby came away from the incident unscathed and was picked up by the family on Thursday, Clark added.

Anderson and his wife, Donna, took their RV “south for a few months every winter,” said John Gilbertson, a longtime neighbor of the Andersons along the southern shore of Big Marine Lake.

Gilbertson said he often saw Anderson, a retiree, walking Toby up and down the road two to three times a day.