Authorities said further investigation of a crash that left three people dead confirmed a downed stop sign was not a factor in the collision.

Rather, St. Croix County Sheriff Scott Knudson said deputies are looking into reports that motorcyclist Cody Cook-Terhurne was driving recklessly in the moments leading up to the crash, reported at 7:10 p.m. Friday, July 19, at Highway 64 and County Road T in the town of Stanton.

Deputies had been alerted to a downed stop sign at the intersection shortly before the collision, but Knudson said witnesses later confirmed the driver of the second vehicle, Thomas J. Plasch, had stopped at the intersection, which is preceded by rumble strips and a "stop ahead" sign.

Plasch, 55, of Oakdale, Minn., and his passenger, 46-year-old Oakdale resident Miriam R. Espinosa, were killed in the crash, along with Cook-Terhurne, a 34-year-old Somerset resident. Plasch's 2008 Lincoln passenger car was northbound on County Road T while Cook-Terhurne was eastbound on Highway 64 when the motorcycle struck the car.

All three were pronounced dead at the scene, according to the sheriff's office, and traffic was detoured for nearly five hours while deputies worked to reconstruct the crash scene. A Monday news release states toxicology results have been ordered through the medical examiner's office.

The release cites witness reports that the motorcycle was "traveling at a very high rate of speed" just before the crash and had been passing vehicles on the right shoulder. The release notes a 7 p.m. traffic complaint from Highway 64 near 170th Avenue - just west of the crash site - about a vehicle and operator matching Cook-Terhurne's description speeding past the caller along the highway's centerline.

"He was driving recklessly, from many citizens' accounts," Knudson said.

Other witnesses reported seeing the Plasch vehicle stop at the intersection.

"There's many people that witnessed a tragedy that unfolded before their eyes," Knudson said.

State records show the intersection was the site of four fatalities between 2005 and 2008. Knudson said traffic safety measures were implemented in the intervening years, including a median turn lane on County Road T and the cutting down of a hill.

While road features were not considered a factor in Friday's crash, Knudson said the St. Croix County Traffic Safety Committee will likely review the crash.

"I'm confident they'll take another look" at the intersection, he said.

These were the sixth, seventh and eighth traffic fatalities in St. Croix County in 2019.

New Richmond Police, New Richmond EMS, Deer Park Fire and Rescue, St. Croix County Highway Department and the St. Croix County Medical Examiner's Office assisted with the incident.

The crash remains under investigation.