The committee report, however, is silent on possible negligence on the part of Mumbai Metro One Private Limited (MMOPL), the Reliance Infrastructure-led consortium in charge of the construction, or sub-contractor Hindustan Construction Company.
“The accident was basically due to voids in the support. The support weakened due to rain and utilities underneath created voids,” said SVR Srinivas, additional metropolitan commissioner at MMRDA.
“So, it was basically due to loosening of the soil due to construction activity and its erosion due to heavy rain that the support weakened. If because of any reason a part of the support settles, stress increases on the staging and causes it to fail leading to a cascading effect,” he said.
Another MMRDA officer said fixing responsibility or looking into negligence was not in the scope of the inquiry.
The committee of K V K Rao, IIT Bombay civil engineering professor, and S B Tamsekar, former PWD chief engineer, recommended the contractor ascertain stability of the sub-strata before beginning such activities.
If instability is observed, remedial measures must be taken to fix it before starting work. The report, to be originally submitted within a fortnight of the accident, reiterates safety checklists should be enforced and construction workers strictly wear safety gear.
MMRDA and MMOPL ordered separate inquiries into the incident. MMRDA said it would not be able to take action based on the report and its probe was more to understand exactly what had gone wrong, while the MMOPL inquiry is internal.