Shuttering between two under construction metro pillars in Lucknow on Sunday collapsed.
The passengers were taken out from the back through the emergency exit.
A French multinational is making the trains at its Sri City facility in Andhra Pradesh.
Mukesh Ambani said he had never seen any city decked up so strikingly as Lucknow
The previous government set up a cabinet task force to clear the backlog of projects but failed to make much of an impact.