Chennai: A Central Industrial Security Force constable at the Chennai airport shot himself dead with his service rifle in a rest room at the airport. The police have identified the 27 year old as Pulak Rajbongshi, from Assam. The reason for suicide is yet to be known. Last year in September, CISF head constable S S Yadhav, guarding the Rajiv Gandhi Memorial in Sriperumpudur, Chennai, shot himself dead after he was allegedly denied leave to visit his family in Uttar Pradesh.