Delhi Metro Rail Corporation issued an official statement after the incident and said a high-level inquiry has been ordered. 

"As per normal procedure prescribed, when a train enters the workshop, the brakes of the train are decommissioned so that the train and its systems including the brakes can be freely checked. As per procedure, once the train is again re-commissioned, the brakes should have been tested by the maintenance staff in the depot before the train left the shed. The train movement inside the workshop area is done manually and not by the signalling system," the official statement read.

 

"Prima facie, it appears, this was not done and subsequently, the person who took charge of the train from the maintenance staff also did not check the brake and proceeded with the train up to the washing plant built on a ramp. While stopping at the ramp, since the brakes were not available, the train rolled back causing this incident."