Three weeks after a major accident on the Versova-Andheri-Ghatkopar Metro brought construction to a halt,work on the corridor restarted two days ago after a review of safety measures. Officials from SGS,a Swiss firm Mumbai Metro One Private Limited (MMOPL) has roped in,is monitoring every construction site for safety. MMOPL is a Reliance Infrastructure-led special purpose vehicle in charge of the 11.4-km elevated corridor. SGS has deployed personnel to oversee safety measures round-the-clock, an MMOPL spokesperson said. Officials maintained impact of the stoppage of work on the 2013 deadline would be minimal. A construction worker died and 16 were injured when an escalator beam being concretized at Airport Road Metro Station collapsed earlier this month.