A youth was killed in hit-and-run accident near Chamra Chowrangi Karachi on Monday, rescue sources said.According to details, an over speeding car knocked down a motorcycle carrying a youth. The youth identified as Faizan was critically injured and car driver sped the scene. The wounded youth was rushed to hospital where he succumbed to his wounds during treatment.The police after registering a case against unidentified car driver started an investigation.