Section 298(2) in The Mumbai Municipal Corporation Act, 1888
(2)When any building, or any part thereof within the regular line of a public street, falls down, or is burnt down, or is taken down whether under the provisions of section 351 or 354 or otherwise, the Commissioner may at once take possession on behalf of the corporation of the portion of land within the regular line of the street theretofore occupied by the said building, and, if necessary, clear the same.