The Bombay plague epidemic was a bubonic plague epidemic that struck the city of Bombay (present-day Mumbai) in the late nineteenth century. The plague killed thousands, and many fled the city leading to a drastic fall in the population of the city. In September 1896, Bombay's municipal administration declared the presence of bubonic plague in the city. Ineffective protocols administered furthering the spread. By January 1897 half the population fled to the countryside. Causes The bubonic plague's arrival in Bombay in the summer of 1896 was part of a deadly pandemic that had originated in China in the 1850s and continued to afflict many parts of the globe until the 1950s. Bombay was made vulnerable by the rapid growth of the city's commerce, which led to a large influx of workers. In the 1891 census, the population of Bombay was counted to be 820,000. Most of the immigrant workers (over 70%) lived in chawls. The city services were not geared towards the well-being of the working class and various diseases were endemic to the slums. Workers in cotton mills, as one of the major social fractions within the city, and as the bedrock of its trade, played a major role in the making of this crisis. The difficulties of sanitary administration arise from the rapidity of decomposition of organic matter, the density of population, and the primitive habits of the people, which have never been brought in line with the necessities of a closely inhabited town having in certain wards a density of 700 per acre. Detection In September 1896, the first case of bubonic plague was detected in Mandvi by Dr. Acacio Gabriel Viegas. It spread rapidly to other parts of the city, and the death toll was estimated at 1,900 people per week through the rest of the year. By March 1897, municipal authorities believed around 20,000 people had died. Many people fled from Bombay at this time, and in the census of 1901, the population had actually fallen to 780,000. Viegas correctly diagnosed the disease as bubonic plague and tended to patients at great personal risk. He then launched a vociferous campaign to clean up slums and exterminate rats, the carriers of the fleas which spread the plague bacterium. To confirm Viegas' findings, four teams of independent experts were brought in. With his diagnosis proving to be correct, the Governor of Bombay invited W M Haffkine, who