Drugs, cold and lack of sleep led to the death of an Iowa trucker

SAC CITY — David Schultz had been working for nearly 30 hours straight with little to no rest breaks the night he parked his tractor-trailer on the side of a country road and drove to an adjacent field last November, the Sac County district attorney said Friday.

The meth-induced trucker from Wall Lake died the next day, November 21, 2023, of hypothermia in the field, about a quarter mile from where his truck, hauling a load of pigs, was found abandoned.

Six months later, on April 24, a farm worker driving a tractor through a field came across Schultz’s body.

Dr. Kelly Kruse, a state medical examiner, listed Schultz’s cause of death as an accident, according to the death certificate, a copy of which was obtained by the Sioux City Journal.

The immediate cause of death is stated in the certificate as “hypothermia due to acute drug poisoning (methamphetamine).” In the “description of injury,” Kelly states: “Ingestion of medication and exposure to cold.”

“The combination of severe sleep deprivation and methamphetamine use is believed to have triggered a medical emergency that caused Schultz to abandon his truck and eventually succumb to the elements in the field where he was later found,” Sac County District Attorney Ben Smith said in a statement Friday.

On November 20, the night Schultz disappeared, temperatures dropped to -1 degrees. The lowest temperature the following day, November 21, was 0 degrees. During the following week, nighttime lows dropped to as low as 11 degrees at times. For three nights in a row, the lowest temperature that week was -8 degrees.

According to the Cleveland Clinic, hypothermia can occur even at temperatures above 40 degrees when people cool down through sweat, rain or immersion in cold water.

In the days following Schultz’s disappearance, local authorities, with the assistance of numerous volunteers, reportedly searched 40,000 acres of land in a wide area around the site where his truck was found to be parked.

“The enormous size of the search area and environmental conditions made it difficult to locate Schultz’s body,” Smith said in a news release. “Search efforts focused on areas of fields where brush and vegetation were present, such as fence lines and field edges, with the belief that a person would be easier to see in open areas. In addition, search teams focused on areas where it seemed more likely that someone was seeking refuge or was trapped.”

The field where Schultz died posed a challenge, Smith said. The corn stalks in the field, both flattened and standing upright, some at about shin height, effectively concealed or camouflaged Schultz’s body, which was lying on its back, he said.

The farm worker, who was preparing the ground for spring planting, did not notice the body until his tractor was about 100 feet away, Smith said.

“I think it was close enough to the road that the search crews thought, ‘We don’t need to look here because we could definitely see him,'” Smith told the Journal on Thursday.

Based on the final autopsy results, the medical examiner ruled out homicide. In the months following the discovery of Schultz’s body, law enforcement also conducted an extensive investigation, but it found no evidence of foul play, Smith said.

“It is clear from the evidence collected at the crime scene and the state of decomposition of the body that Schultz was at the crime scene for months,” Smith said in the statement.

Investigators found that Smith had been behind the wheel of his truck for nearly 30 hours and had little to no sleep as he tried to support his business and young family.

Schultz, a married father of twin sons, was last heard from in the early morning hours of November 21. On the evening of November 20, he had driven to a hog pen near Eagle Grove to pick up a load of hogs and take them to a hog purchasing station in Sac City.

Video footage showed him at a rest area near Fort Dodge at about 11:15 p.m. on November 20. After leaving the rest area, his truck was traveling west on US Highway 20. After reaching the intersection of Highways 20 and 71, the truck turned north onto Highway N-14 instead of heading south toward the Wiechman Pig Station in Sac City, its intended destination.

His Peterbilt semi-truck was parked in the middle of the northbound lane of County Road N-14, not far from the intersection with D-15 in rural Sac County. Cellphone data shows the truck may have been there since 12:40 a.m. on Nov. 21. A county road worker spotted the truck later that afternoon.

The truck was reportedly parked, with the lights off and the keys in the ignition. Officers found Schultz’s wallet and cellphone inside. A towel, cellphone charger and pocket knife were found across the street along with his coat, according to Sac County Sheriff Ken McClure.

His mysterious disappearance attracted worldwide media attention and sparked an outpouring of support for Schultz’s family. His wife Sarah posted almost daily Facebook updates about the search for her husband and details of his life, attracting numerous followers.

Dolly Butz, Mason Dockter and Jared McNett of The Journal contributed to this report.