  The nation-wide lockdown starting 25 March 2020, aimed at suppressing the
spread of the COVID-19 disease, was extended until 31 May 2020 in three
subsequent orders by the Government of India. The extended lockdown has had
significant social and economic consequences and `lockdown fatigue' has likely
set in. Phased reopening began from 01 June 2020 onwards. Mumbai, one of the
most crowded cities in the world, has witnessed both the largest number of
cases and deaths among all the cities in India (41986 positive cases and 1368
deaths as of 02 June 2020). Many tough decisions are going to be made on
re-opening in the next few days. In an earlier IISc-TIFR Report, we presented
an agent-based city-scale simulator(ABCS) to model the progression and spread
of the infection in large metropolises like Mumbai and Bengaluru. As discussed
in IISc-TIFR Report 1, ABCS is a useful tool to model interactions of city
residents at an individual level and to capture the impact of
non-pharmaceutical interventions on the infection spread. In this report we
focus on Mumbai. Using our simulator, we consider some plausible scenarios for
phased emergence of Mumbai from the lockdown, 01 June 2020 onwards. These
include phased and gradual opening of the industry, partial opening of public
transportation (modelling of infection spread in suburban trains), impact of
containment zones on controlling infections, and the role of compliance with
respect to various intervention measures including use of masks, case
isolation, home quarantine, etc. The main takeaway of our simulation results is
that a phased opening of workplaces, say at a conservative attendance level of
20 to 33\%, is a good way to restart economic activity while ensuring that the
city's medical care capacity remains adequate to handle the possible rise in
the number of COVID-19 patients in June and July.
