New Delhi: A train on Delhi's Metro's soon-to-be-launched Magenta Line rolled into the maintenance depot and crashed through its wall on the west bank of the Yamuna on Tuesday after the staff apparently forgot to apply the brakes.

According to a statement by the Delhi Metro Rail Corporation (DMRC), the train, whose brakes were disengaged, rolled down a ramp at Kalindi Kunj around 3.40pm into the washing plant and crashed into a wall before coming to rest in front of a ditch.

The trains are driverless but will have drivers for the first two-three years.

The statement said: "When a train enters the workshop, the brakes 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."

The statement added: "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."

DMRC sources said the launch of the Magenta Line, which will connect west Delhi with Noida, by Prime Minister Narendra Modi will be done as scheduled on December 25.