Sreedharan in Delhi. (Prem Singh)

New Delhi, July 12: Tragedy struck Delhi’s showpiece Metro railway this morning when an under-construction bridge collapsed and killed six people, raising suspicion that the rush to meet next year’s Commonwealth Games deadline was taking a toll on safety.

Sources blamed the 5am accident — that killed five labourers and 28-year-old site engineer Anshuman Pratihar from Bengal and injured 15 other workers — on cracks in a pillar being ignored for three months. Residents of the south Delhi neighbourhood, Lajpat Nagar, said the toll would have been far higher had it been the rush hour on a weekday.

In a move tinged with irony, Delhi Metro chief E. Sreedharan quickly tendered his resignation on moral grounds, and the state government rejected it.

Sreedharan has been feted as the “Metro Man” for his ability to meet deadlines in a country where delays blight infrastructure projects; but he has also been accused of putting staff under intense pressure through his emphasis on speed, causing them to take short cuts.

The Delhi Metro, engaged in extending several lines that must be completed by June 2010, has witnessed at least five mishaps at construction sites in the past two years. A partial bridge collapse last October, and other instances of falling slabs and beams, killed four people in all and injured many.

Metro sources pointed to Sreedharan’s habit of trying to complete projects well before time.

“If a project is to be completed in two months, Sreedharan would insist the work gets done in a month. This has sometimes worked well but there comes a time when pressure takes its toll. They (staff) are human after all,” an official said.

It was the faulty Pillar 67 that collapsed, causing a portion of the bridge to crash down on the road below where 30 people were working. “We had warned senior officials but they didn’t stop work. They just did a few structural repairs and passed the pillar as feasible,” a source said.

Insiders also alleged the Metro had reduced the number of supervisors at the bridge site, shifting some to other projects.

Sreedharan, 77, Delhi Metro’s managing director since its inception 12 years ago, denied receiving any complaints. He, however, told a news conference: “It may not be my mistake, but as the head of the organisation I have to take moral responsibility.”

Officials said the line was now expected to be completed in September 2010, weeks before the start of the Games that has sparked a development frenzy in Delhi, and for which this year’s budget has earmarked Rs 30,000 crore.

P.K. Sarkar, head (transport), School of Planning and Architecture, cited two possible reasons for the accident. “It could be a design fault, meaning the designer was unable to estimate proportions of mixture needed for the pillar, or a construction fault — the contractor didn’t follow the designer’s specifications.”

A four-member probe committee will hand in its report in 10 days. The police have registered a case of “death by negligence”, punishable by up to two years in jail, against construction company Gammon India Limited, a contractor it had hired, and a supervisor.

Gammon India had been one of the contractors also for the flyover that collapsed in Hyderabad in September 2007, killing five. A probe panel had recommended action against the company.