Wolverton, MN — September 25, 2025, Nicolas Terfehr was killed and Darin Differding was injured due to a truck accident at approximately 4:30 p.m. on C.R. 3.

According to authorities, 40-year-old Nicolas Terfeher was traveling in a northbound tanker truck and 44-year-old Darin Differding was traveling in a northbound road grader on County Road 3 in the vicinity southeast of Wolverton when the accident took place.

Officials indicate that, for as yet unknown reasons, a collision took place between the tanker and the road grader. Both vehicles went into a ditch, the grader coming to a stop resting on its roof, while the tanker stopped on its wheels, reports state. At least one of the vehicles caught on fire as a result of the collision.

Terfehr reportedly sustained fatal injuries over the course of the accident. Differeding suffered non-life-threatening injuries, as well; he was transported to an area medical facility by EMS in order to receive necessary treatment. Additional details pertaining to this incident are not available at this point in time. The investigation is currently ongoing.

Commentary by Attorney Michael Grossman

When a fatal collision occurs between a tanker truck and a road grader on a rural county road, people tend to view it as a freak accident—two large work vehicles somehow in the same place at the same time. But from a legal standpoint, the presence of slow-moving or obstructive equipment like a grader on an active roadway isn’t unusual. What matters is whether the collision could—and should—have been avoided.

The early information suggests both vehicles were traveling in the same direction. That immediately raises key questions about visibility, speed, spacing, and communication. Was the road grader operating with appropriate warning signage, flashing lights, or a follow vehicle, as is commonly required? Was it visible from a distance? Did the operator signal any intention to slow, stop, or shift positions in the lane?

On the other side of the equation, the tanker truck driver would have had a duty to recognize and respond to a slower-moving vehicle ahead—particularly on a straight rural road with limited traffic. If the truck was following too closely, distracted, or attempting to pass without sufficient clearance, that could point to driver error. A slower vehicle isn’t a hazard by itself; it becomes one when someone behind fails to adjust.

The fact that the crash resulted in both vehicles leaving the roadway—and possibly catching fire—suggests significant impact force. That level of violence raises further questions about the truck’s speed and braking prior to contact. Those questions aren’t hypothetical—they can be answered with ECM data from the tanker, physical evidence from the scene, and eyewitness accounts, if available.

Finally, the use of heavy equipment on rural roads is not unusual, but it must be properly managed. If the road grader was operating without proper escort, lighting, or coordination with local traffic authorities, then liability may not rest solely with the truck driver. In my experience, cases like this often reveal breakdowns in planning and communication between public agencies, contractors, and individual operators—all of which should come under scrutiny during the investigation.

Key Takeaways

• The central issue is whether the tanker driver had enough warning and distance to avoid the slower-moving grader.
• Investigators should review ECM data, brake records, and visibility conditions to evaluate the truck’s response.
• Proper signage, lighting, and escort procedures for the grader must be confirmed as part of the inquiry.
• Shared direction of travel raises questions about following distance and situational awareness, not just speed.
• Responsibility may rest with either or both operators—or with the parties that coordinated the grader’s activity on the roadway.