Preliminary responses from various divisions of the railways today indicated that human error might be at the bottom of a train accident that claimed 20 lives in Uttar Pradesh on Saturday. It now appears that some repair work on the tracks was in progress, of which the station master of Khatauli, the nearest station, claimed to have been unaware. "Some maintenance work was going on, which might have caused the derailment of Utkal Express," said Mohd Jamshed, Member Traffic, Railway Board, at a press conference today.