(ELMWOOD TOWNSHIP) -- Tuscola County Sheriff's deputies continue to investigate a multiple vehicle crash that took place around 1 p.m. Monday on M-81 at Cedar Run Road. Deputies say the incident involved an eastbound vehicle driven by 41-year old Philip Rancilio of New Baltimore, Michigan, which was rear ended as he was stopped in the roadway waiting to make a left turn onto Cedar Run. The second vehicle was driven by 46-year old Jennifer Guinn of Unionville. Following impact, deputies say the Rancilio vehicle swerved into the westbound lane and struck a mail carrier vehicle driven by 52-year old Rachel Maurer of Snover, head on. Both Maurer and Rancilio were transported to Saginaw area hospitals for treatment. Guinn and her passenger, 21-year old Brandalyn Plowman of Fairgrove, were taken to Hills and Dales Hospital in Cass City for treatment. Deputies were assisted by the Sheriff's Department Accident Reconstructionist, Cass City Police, Cass City Fire, Gagetown Fire, EMS personnel and the Tuscola County Road Commission.