Satre, who reviewed preparedness ahead of the monsoon in a meeting here, took a note of an observation that last time it took three to four hours for NDRF to reach the mishap (building collapse) site.
The issue of several dangerous buildings in Thane, Kalyan and Dombivili region was also discussed, an official release said.
The meeting was informed that boulders crash on the Konkan railway route on several occasions and this time Railways have identified 64 "dangerous places" where the boulders are likely to crash, it added.