India, Feb. 24 -- Alarmed by the February 14 metro slab collapse incident in Mulund, several residents appear to be doing the job of highly paid consultants by monitoring the condition of under-construction metro rail corridors and demanding better quality of work from the Mumbai Metropolitan Region Development Authority (MMRDA).

The development authority has been addressing a flurry of complaints on social media from vigilant citizens pointing out apparent flaws in the construction quality of metro rail infrastructure, officials said. These include photographs and videos of possible cracks, gaps, and engineering defects in the girders, boundary slabs, and pillars.

The most recent such complaint came on Sunday on a stretch of Metro 4, t...