The engine of Visakha Express got detached from its coaches between Narsipatnam and Tuni railway stations on August 19. Visakha Express plies between Bhubaneswar to Secunderabad. The engine travelled at least 10 km without coaches. The official, however, could not explain the reasons for the uncoupling of the engine and the bogies when the train was on the move. Investigation is underway in this regard.