An arrest affidavit obtained by Your Group Ride outlines the actions of a construction flagger in the moments before a fatal crash involving Cate Withrow on July 6th in Fort Collins. Rudolph Nickolas Baldivia has been charged with criminally negligent homicide in connection with Withrow’s death.
Trigger warning: The following article contains details of a fatal bicycle crash, including the circumstances of the collision, that some readers may find distressing.
My thoughts are with Rick, their girls, Cate’s brother and parents, her family, and all of Cate’s friends, students, colleagues and members of the community who are grieving her loss.
According to the affidavit, Fort Collins police were dispatched at approximately 6:22 p.m. to the intersection of East Mulberry Street and Whedbee Street, where a semi-truck had struck a bicyclist.
The crash happened in a road construction zone where crews were milling pavement on East Mulberry Street. Westbound lanes were closed, and traffic was being directed through a single eastbound lane operating along the south side of the roadway. Several semi-trucks were lined up waiting to be loaded by the milling machine.
Investigators reviewed dash camera footage from two trucks at the site. The footage showed Baldivia, who was working as a flagger, in the intersection wearing a reflective vest and hard hat. His STOP/SLOW paddle was leaning against a road barricade rather than in his possession.
The footage showed Baldivia raise an arm and motion toward Withrow as she approached on her bicycle from the north. Withrow stopped riding, straddled her bicycle and pushed it forward with one foot. Baldivia then pointed to the ground in front of the semi-truck, directing her to stop there.
According to the affidavit, Withrow and Baldivia were positioned near the front passenger-side bumper of the truck, watching traffic in the open lane. A witness described them as standing a couple of feet from the bumper.
Radio communications instructed the trucks to move forward, which investigators described as part of the normal milling operation. The affidavit states there was no direct communication between the truck drivers and the flaggers. Approximately 12 seconds after Withrow moved in front of the truck, it began to move.
Video reviewed by investigators showed Baldivia appear to recognize the danger and move toward Withrow. The truck struck her, and the bicycle was pushed downward. Withrow fell to the ground and was run over by the truck’s front right steer tire. Baldivia was also struck by the bicycle as it was pushed to the ground, but was able to move out of the way and was not injured. Withrow died at the scene.
The affidavit describes a blind-spot study conducted by the Fort Collins Police Department CRASH Team. Investigators determined that the ground directly in front of the truck would not be visible to the driver until it was approximately 41 feet and 11 inches in front of the vehicle, near the center of the hood. The affidavit states the driver could not have seen a person standing in the location where Withrow had been directed to stop.
Baldivia had worked as a flagger for Hire Quest since January 2018. The affidavit says his employer described him as experienced and noted that he was sometimes specifically requested for jobs. He held flagger certifications through the Colorado Department of Transportation and Hire Quest and had most recently completed recertification on March 20th, 2026.
Investigators reviewed flagging requirements and training materials, including the Manual on Uniform Traffic Control Devices, the 2026 CDOT Flagger Training Manual and the City of Fort Collins’ Work Area Traffic Control Policies and Procedures. The affidavit states that flaggers are required to carry their STOP/SLOW paddles while working in a construction zone and must recognize dangerous traffic situations.
According to the affidavit, Baldivia told investigators that flaggers did not use their paddles in intersections because doing so could confuse traffic. Investigators said other traffic-control specialists disputed that explanation. The affidavit also states that Baldivia did not recognize the danger of directing Withrow to stand so close to a truck that was expected to move, particularly when there was no direct communication between the flaggers and truck drivers.
The investigating officer also consulted safety expert Greg Gerganoff, whose professional experience includes more than two decades in workplace safety. Gerganoff reviewed the case information and provided an opinion that Baldivia’s failure to perform his duties resulted in Withrow’s avoidable death.
In the affidavit, the officer concluded that Baldivia’s actions placed Withrow in an unsafe position in front of the semi-truck and that his failure to recognize the risk represented a gross deviation from the standard of care expected of a trained and experienced flagger. The affidavit was submitted in support of an arrest warrant alleging criminally negligent homicide.
Baldivia remains in the Larimer County Jail. No bond has been set. He is scheduled for a hearing on advisement at 1:30 p.m. November 5th in Larimer County District Court. His first appearance is scheduled for November 12th at 8:30 a.m. in person.
The charge is an allegation, and Baldivia is presumed innocent unless and until proven guilty in court.
