New Delhi, July 12 - 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.