(COLDWATER) - Michigan State Police say a fatal Interstate 69 crash that killed a Branch County Road Commission employee remains under investigation as authorities await toxicology test results from the driver of a semi-truck involved in the collision.
The crash happened June 5 when a semi-truck rear-ended a tractor mower being operated by 46-year-old Casey Rice as he was mowing along the shoulder and median of the interstate.
Rice died two days later at a Kalamazoo hospital.
Investigators suspect drug impairment may have been a factor in the crash and are waiting for blood test results before determining whether an arrest should be made or criminal charges sought.
State police say the semi-truck driver was released after receiving medical treatment while the investigation continued.
Once laboratory testing is complete, investigators will submit the case to prosecutors for review and a determination on any possible charges.
Michigan State Police have not provided a timeline for when the toxicology results or the investigation will be completed.