CHENNAI: An empty coach of the Jan Shatabdi train derailed today morning when it was being taken to the yard for cleaning. The incident took place near the Basin Bridge junction at around 2.30 a.m. when the train was being taken from Dr MGR Central Railway Station to the yard for routine cleaning works. Railway staff struggled for nearly one hour to re-rail the wheels of the derailed coach back on the track after which it was taken to the yard. The cause of the derailment is being investigated, Southern Railway sources said.