Bhubaneswar, June 3 : Nearly 18 hours after the massive train tragedy in Odisha's Balasore district, restoration work has begun at the accident site, said Railway Minister Ashwini Vaishnaw. The overturned coaches are being removed from the tracks through cranes, he said. "We will conduct a detailed investigation to reach out the root cause behind the accident and we will take necessary steps to ensure that such an accident will not reoccur in future," Vaishnaw said. Union Education Minister Dharmendra Pradhan, who was at the accident site, sought cooperation from the locals to carry out the restoration and relief work by the Railway. He also thanked the locals for extending help in the rescue operation. Meanwhile, West Bengal Chief Minister Mamata Banerjee reached the accident spot. She will take stock of the rescue work and interact with the injured passengers from West Bengal at the hospital. The death toll in the massive accident of three trains including two express trains rose to 261. According to information given by South Eastern Railway, the death toll in the train tragedy has been increased to 261 and the figure may go up as rescue operation is yet to complete. Over 900 persons have been injured in the mishap. The injured passengers have been admitted in Gopalpur, Khantapara, Balasore, Bhadrak, Soro and Cuttack SCB hospitals, the Railway officials said. /IANS