Bubonic plague struck in 1898 and killed thousands in the crowded old town. The government's response was to build new, well-ventilated, planned suburbs with wide roads, parks and drainage. Basavanagudi and Malleshwaram were laid out around 1898–1900 and remain some of the most liveable neighbourhoods in the city.
Around the same time the city installed a modern piped water supply and set up health inspection services. See the Malleshwaram and Basavanagudi guides.
Further reading: Malleswaram on Wikipedia.