SIOUX FALLS | The South Dakota Highway Patrol says it has been unable to determine the cause of a crash in February that killed four members of a Sioux Falls family.
Fifty-two-year-old James Vollmer was driving along Interstate 90 near Sioux Falls on Feb. 23 when the car drifted off the interstate and into a median. Killed with Vollmer was his 48-year-old wife Julie; 16-year-old daughter Allysa; and 13-year-old son Caleb. All four occupants were wearing seatbelts.
Capt. Kevin Joffer with the Highway Patrol says an autopsy found no evidence of a medical problem or condition that could have contributed to the crash. There also was no evidence of a mechanical failure or problem, driving under the influence or texting or cellphone use.