New Delhi, July 12 - In the worst accident in the history of Delhi Metro, five people were killed and 15 injured when an elevated section of the tracks under construction came crashing down Sunday morning. Delhi Metro Rail Corporation (DMRC) chief E. Sreedharan, though not directly responsible, owned the 'moral responsibility' and stepped down.

The concrete slabs that collapsed were part of an elevated section of a new Metro route between the Central Secretariat and Badarpur section. The accident took place around 5 a.m. at the construction site at Zamrudpur near Kailash Colony in south Delhi.

A launching girder along with a portion of the elevated tracks set up on pre-fabricated pillars collapsed with an ear-splitting noise.

Sreedharan said the incident took place between pillars 66 and 67 when the pillar cap was affected. Ten segments were to be erected on the stretch, of which five had been completed. When the sixth segment was being erected, the launching girder - one of the longest - collapsed due to disbalance.

'The 4.23-metre long cantilever (which collapsed) was longest to be used in any of the DMRC project. It was holding two girders - one launching girder and the girder to be erected,' the DMRC managing director told a press conference later in the afternoon.

'Twenty people who were working on it got injured, and out of them, five were killed. The injured were rushed to various hospitals,' he said.

Sreedharan, the 77-year-old technocrat who has earned the sobriquet of India's 'Metro man' and has been honoured with Padma Shri for his exemplary public service, owned 'moral responsibility' for the crash and quit.

'I have been in charge of the Metro since the beginning. I take full responsibility for the accident, and having taken the full moral responsibility I resign as the managing director of the Delhi Metro,' he told mediapersons.

'I may not be directly connected with the accident. But I am the head of the organisation and have to take the moral responsibility,' Sreedharan added.

However, Delhi Chief Minister Sheila Dikshit said that the decision over his resignation would not be taken in haste.

The DMRC has constituted a four-member high-level technical committee to probe the accident.

This Metro section was slated to open by September 2010, a month before the Commonwealth Games the capital will host.

'Due to this accident, the estimated damage is Rs.6 crore (Rs.60 million) to the whole work. This accident is going to cause a serious delay. We anticipate on this section a delay of at least three months,' said Sreedharan.