As I recall, Russ, that ambulance was being driven by an 'older' gentleman (I was only 21 at the time!) named Don Clark... who lived across the street from my family's home in Jackson (MI). I believe he lost control of the vehicle on an icy roadway and slid into a tree, fortunately injuring no one (except the ambulance!) seriously. Coincidentally, Mr. Clark's brother, Richard, would subsequently start a 'rival' service (to HORNE-VINSON), "Jackson Transport Ambulance," shortly afterward.
On a side note, I had occasion to speak with Geroge Vinson, Sr., one of the HORNE-VINSON co-owner's, just a few months ago... reconnecting after more than 30 years! Although retired from the ambulance service since 1979, when he sold that facet of his funeral home business to what would later become "Jackson EMS" (now "Jackson Community Ambulance"), he still spends the summer months living near Jackson, while 'wintering' in Florida. Mr. Vinson promised that he would check his archives upon returning to Michigan this summer, and share with me any remaining photographs he may have of the 1960s-vintage ambulances HORNE-VINSON operated... vehicles I was totally captivated by as a young boy and spent countless hours drawing pictures of!
Stay tuned...