The shock wave of a blast centred in the Fort area would destroy more or less completely a circle with a 1.1-kilometre radius. Most of the buildings from Colaba to Victoria Terminus, along the entire width of the island, would be destroyed. All kuchha houses up to 1.7 km from the point of explosion would be destroyed. The winds accompanying the shock wave, reaching speeds of over 110 km/h to a distance of 3 km or more, would destroy many more buildings. One has to remember that many of the city's buildings, especially older ones, are poorly constructed and are liable to collapse due to the shock wave and the hurricane-speed winds even if they are far from the epicentre.
Within a few minutes the fires ignited by the flash of light and heat would start to coalesce into super-fires, engulfing an area within a radius of up to 2 km. The temperatures in the fire zone could reach several hundred degrees. The high heat covering such a large area would act like a large pump sucking in air from surrounding areas. The inward winds would reach speeds of 50-80 km/h.
The combination of high winds, thick smoke, destruction of water mains, debris blocking access routes, as well as destruction of men and materials would make effective fire-fighting impossible. The chance of citizens in the blast area escaping the firestorm would be slim.
Unlike the cities that suffered firestorms during World War II due to aerial bombings, the fires in Bombay would be much worse because of the many secondary explosion which would take place in the wake of the heat and fire of the nuclear blast. These would include explosions of gas cylinders in household kitchens, diesel and gasoline tanks of motor vehicles, pump stations, as well as industrial neighbourhoods full of flammable and toxic materials. India's highest concentration of chemical industries is in the trans-Thane creek area, which has over 2000 factories. Central Bombay itself is home to several mills.