Airdrie Rural RCMP are investigating a deadly crash that claimed the lives of a mother and her infant daughter near Kathryn, on Tuesday night.Police say the collision happened around 10 p.m. at the intersection of Hwy. 566 and Hwy. 9 when a Dodge Ram pickup heading northbound struck a semi heading southbound. The truck erupted in flames after impact.The semi driver escaped without injury, but the 36-year-old woman from Hanna and her 18-month-old passenger were pronounced dead at the scene. Two other children in the pickup were rushed to a Calgary hospital with injuries.The cause of the crash remains under investigation. RCMP have offered condolences to the family and friends of those affected.