Bhubaneswar, June 4 : The Commissioner Railway Safety has completed its inquiry into the tragic train accident in Odisha's Balasore district and the root cause has been identified, said Railway Minister Ashwini Vaishnaw on Sunday. Vaishnaw, who was there at the accident spot and supervising the restoration work, said, "The Commissioner Railway Safety has completed his inquiry and will submit the report soon. The clear root cause of the tragic train accident has already been identified." However, he did not reveal the cause behind the accident, which killed at least 288 people and left over 1,100 people injured. As per the instruction of Prime Minister Narendra Modi, who inspected the accident site on Saturday, restoration work is going on in full swing and the restoration will be completed by Wednesday morning, the Minister said. In a statement, South Eastern Railway (SER) said all 21 coaches which capsized and derailed have been grounded. Now the site is being cleared from bogie/wheel sets and other components. "Three goods wagons and locomotive grounding work is going on. Track linking and OHE work is going on parallel," it said. /IANS