New Delhi, Dec 20 (IANS) The Delhi Metro on Wednesday sacked four of its officials, including a Deputy General Manager, for Tuesday's accident in which a metro train rammed through a wall after failure of its brakes.A three-member committee was formed after the accident on the Magenta Line to look into the causes."The four officials included one Deputy General Manager who was the Depot Incharge, one Assistant Manager under him responsible for this depot activity and a Junior Engineer and Assistant Section Engineer who were involved in operating this train."The suspension is based on the enquiry done by a team of three Executive Director rank officials," the Delhi Metro Rail Corporation (DMRC) said in a statement.The accident which happened inside the Kalindi Kunj metro depot located on the upcoming Magenta Line (Botanical Garden - Janakpuri West) was a result of "human error", the transporter said, arising out of "not following proper procedure"."The train's brakes, which were isolated (necessary for push/pull operations in the depot area when a train is required to move with a battery operated vehicle) were not normalized before moving the train on its own power and bringing it for washing at the ramp."As a result, as soon as the operator brought the train at the ramp, it started rolling back, got derailed and hit the wall," the DMRC said.A segment of the line (Botanical Garden-Kalkaji Mandir) which is ready for operation, is scheduled to be inaugurated by Prime Minister Narendra Modi on December 25.Though the new line will see trains which are enabled to be driven without drivers, it will have trains run by drivers initially with "high level of automation". The driverless train function will be brought thereafter.--IANSvn/rn