A youth was on Tuesday mauled to death at Delhi Zoo by an adult white tiger when he accidentally fell into the enclosure while climbing its fence to take a picture. Though it is not clear how the youth, in his early 20s, fell into the enclosure, eyewitnesses said he had tried to climb the fence but slipped. The tiger did not attack the youth for a few minutes but became violent after someone threw a stone at it and guards started hitting the fence. "The tiger then grabbed him by his neck and dragged him away," an eyewitness said. Some eyewitnesses claimed that the security guards at the Zoo could do nothing to help the youth when he was being dragged away by the tiger as they did not have tranquiliser guns. The horrific incident was filmed by an eyewitness which showed the tiger holding the youth by his neck and then killing him. Police and Zoo officials were unable to take out the body from the enclosure even hours after the incident. Zoo authorities declined to comment about the gruesome incident immediately.