Perth County OPP were at the scene of a crash just east of Listowel on Monday.
Police say the crash occurred at the intersection of Wellington Road and Concession 3.
Three were injured with 2 taken to hospital with non life threatening injuries and another airlifted to hospital with life threatening injures.
Investigation is still ongoing with witnesses asked to contact police at 1-888-310-1122.
Updates will be provided as they are made available.