Calamity happened last week it not natural. Its a manmade.
Certain measures to avoid calamities in future:
1) Demolish extra construction which puts strain on sanitary facilities. 2) Simple & good is to close all the open gutters in suburbs. People here have a tendency to throw the garbage in open gutters. Widen the way of gutters. Put big pipes for drainage. Gutters in Mumbai upto Sion & Mahim are closed so Mumbai City area always looks beautiful than suburbs. Garbage piles are always very sligher in city than suburbs. Construct pavements to walk. 3) Remove all the slums & restore only those slum dwellers whose 2-3 generations are surviving here till now. 4) Keep check on increasing population constantly. There is limit on rush & it should be controlled. 5) Develop like Mumbai other places of the country also so that large part of population will not flow only in Mumbai.
