New Delhi, May 4 -- The Municipal Corporation of Delhi (MCD) on Sunday said it is probing building by-law violations after nine people were killed in a massive fire at a four-storey residential building in Vivek Vihar, with a focus on the installation of an iron grill, the number of dwelling units relative to plot area, and the width of the single staircase.

A senior MCD officer, who asked not to be identified, confirmed that the probe was initiated at the zonal level and headquarters separately. "The probes are being conducted to check the width of the staircase, installation of iron grills across four floors, and the number of dwelling units compared to the plot area. Prima facie, officials found that iron grills covered the entire rea...