Blaming "deficiency" in design and material for the recent mishap, Delhi Metro on Tuesday issued a notice to contractor Gammon India asking it to explain why it should not be blacklisted for two years and suspended two of its deputy chief engineers.

Gammon India, however, will be allowed to complete the five projects, including the much-awaited Noida corridor, which it is undertaking currently, DMRC Managing Director E Sreedharan said.

Making public the findings of the A K Nagpal committee that probed the collapse of an under-construction bridge in Zamrudpur on July 12 in which six people were killed, he blamed the consultant firm, Tandon Constructions, of "misleading" the DMRC and the contractor on the crack.

"The crack on pier 67 was first noticed on April one and we approached them on April three. They gave us a report on April 15 saying that there was no inadequacy in the design.

The consultant misled the DMRC and contractor," Sreedharan said.

"We have accepted the report (Nagpal panel) in total.

The unfortunate incident took place due to design deficiency and material deficiency. The cantilever design was not adequately taken care of and provision of steel at different points were not adequate," he told reporters here.