Traffic on Highway 501 was backed up Thursday afternoon because of a crash involving an ambulance. Conway police responded to a report of a stolen medical transport vehicle in the 300 block of Singleton Ridge Road. Shortly thereafter -- and around the corner -- a medical transport van from Coastal Medical Transport crashed into a ditch on the side of Highway 501 near the front of Burning Ridge Golf Club, across the highway from Aldi. A witness who came upon the crashed ambulance before first responders were on the scene said he saw a person wearing a medical bracelet walking away from the scene of the smoking vehicle. South Carolina Highway Patrol is leading the investigation, but no further details have been released.