One person was killed while three others sustained injuries when two cars collided head on at Trai Timergara in the wee hours of Wednesday. Police and local sources said that four friends Asghar Khan, Naeem Khan, Fazali Rabbi and Malik Fakhar Hayat were on their way back from Lahore to Timegara when the incident occurred as a result of which Malik Fakhar Hayat the National Youth Organization Lower Dir chapter president was killed while his friends Asghar, Naeem and Fazali Rabbi sustained injuries.