 At around 7 a.m, an explosion was heard by the security guard, Sudhir Kumar, who then discovered smoke in the transformer room.The fire brigade and the Delhi Vidyut Board (DVB) were informed and the fire was brought under control by 7.25 a.m.Inspection of the transformer by the Superintendent of the DVB and his team revealed that three of the low tension cable leads of the transformer had been partially burnt.