Covid-19: What drove India close to 100,000 coronavirus deaths

India is on the verge of reporting 100,000 deaths from the coronavirus - a grim toll that ranks it third in the world behind only the US and Brazil.

September was the nation's worst month on record: on average 1,100 Indians died every day from the virus. Regional anomalies continue as some states report far higher deaths than others - a sign, experts say, that the pandemic is still working its way through the country.

Here's some of what we know about where India is worst affected by Covid-19 and why.