S K Mittal, Commissioner for Railway Safety, Southern Railway, had held a statutory inquiry into the derailment.
"According to the provisional findings of the Commissioner appended with his preliminary report, the accident occurred due to 'Failure of Equipment-Weld Failure'," an official release here said.
These findings were under the consideration of the government, it said without elaborating.
11 bogies of the train had derailed at Sitheri, about 90 km from here, on April 10.