NEW DELHI - A large crack in a pillar of the underconstruction bridge of the Delhi Metro in south Delhi could have caused its collapse early Sunday, killing five people, say workers engaged at the accident site.

Five people, including a site engineer, were killed and 15 were injured in the accident that took place at around 5 a.m. at Zamrudpur near East of Kailash, Delhi Metro Rail Corporation (DMRC) officials said.

Thirty workers of the contractor company Gammon India Ltd were present at the construction site when the bridge collapsed.

Many strongly criticised Gammon and DMRC authorities for negligence saying they had complained several times about a faulty pillar.

Said Kishan, a construction worker present at the site: “There was a crack in the pillar and we had complained to authorities on various occasions. The engineers came and suggested that support should be given to the pillar by inserting wires and putting boulders against the pillar.

Another worker said: We told them that the crack was there and if not corrected the pillar would be faulty and would cause the segment to come crashing down - now it has.

Even residents of nearby residential colonies say they had seen a visible crack.

A resident of Amar Colony, who identified himself as Dr. Tiwari, told IANS: There must have been something faulty with the design. Because we had seen a very visible crack in the pillar. We thought the stretch was still under-construction so we did not bother - but now this! Officials will have to probe the negligence of the Metro and the contractor company.

Meanwhile, metro officials have held that the incident occurred because the launching girder of a segment of the bridge lost balance.

“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 collapsed due to disbalance causing a portion of the bridge to fall,” DMRC spokesperson Anuj Dayal said.