New Delhi: The Delhi high court on Wednesday summoned the chief of Municipal Corporation of Delhi to appear before it and explain the civic body's failure to repair a drain pipe discharging contaminated water in a waterbody in the city zoo, leading to death of several black bucks. A division bench of Chief Justice Dipak Misra and Justice Sanjiv Khanna asked MCD commissioner K S Mehra to appear on July 21 and explain the civic agency's failure in carrying out repairs despite the court order. The bench passed the order after a three-member panel set up by it submitted a report saying that the civic agency had partially repaired the drain and left some of its portion unrepaired saying it falls under the jurisdiction of the Railways and National Zoological Park. The committee submitted that despite the repair work, there were chances that during monsoon the sludge would flow into the animals' enclosures from the drain.