The accident comes nine months after the collapse of a portion of an under-construction bridge in east Delhi's Laxmi Nagar, that killed two labourers.
The collapse of an under-construction over-bridge in South Delhi today was the second major accident in the history of Delhi Metro, which enjoys a "fine reputation".
The accident at Dharmroodpur in south Delhi this morning, that has claimed five lives so far, comes nine months after the collapse of a portion of an under-construction bridge in east Delhi's Laxmi Nagar, that killed two labourers.
Prima facie, a Delhi Metro official said, today's accident took place due to a "problem in the design" of the pillar.
Chief minister Sheila Dikshit today said that she expected the Delhi Metro, which enjoys a "fine reputation", will take appropriate action against those responsible for the mishap.
The Delhi Metro in its nearly decade-old history has also witnessed smaller accidents at its construction sites.
On June 30, a Delhi Metro crane hit a Wagon R car in a chain collision on Mehrauli-Gurgaon Road but no one was injured.
In another incident, a prisoner was injured after he got dragged by a Metro train across the length of the Chandni Chowk platform on September 30 last year.
A crane at the construction site near Ram Manohar Lohia Hospital, after developing defects, dropped a four-tonne iron beam on a passing car in July, 2008 in which one person suffered serious injuries.