The Bengal Famine was perhaps the worst thing which happened to India under the rule of the British Empire. It killed over 3 million people and still today the anger, shock and sadness is still felt by the people living in bengal who died of starvation.
India was Britain's prized colony where it would export most of it's gold, food and other natural resources. It would also be the place where factories would be created and workers would be employed to keep generating profit from cheap labour in India.
However, until 1943 you'd think that Britain would develop some sense of humanity, but nope and not when it comes to it's colonies at all, because Indians under the rule of India were treated as second class citizens and at this point it reached a boiling point where Indians couldn't tolerate being subjugated to discrimination any longer and the Britons couldn't pay for costs of maintaining order in India, especially with the ongoing war in Germany.
The Bengal Famine in 1943 swept across Bengal and killed almost 3 million people, a catastrophic event which raised fire in the hearts of every Indian. That famine was caused by the "hero" Winston Churchill as he decided to export food grew in India to Britain to the solders and keep their army alive, at the cost of Indian lives.
He was asked by Indians, specifically in a letter wrote to him by Ghandi on how to tackle this issue, he replied with a:
Why isn't Ghandi dead yet.
Churchill wouldn't even let some of the American and Canadian aid ships to reach India and help with the crisis, instead the government of India with their slow efforts, as well the local government of bengal did what they could to to reduce the damage, but alas people still died.
British Empire, like most empires in history was built upon the death, labor and sacrifice of the people and countries it conquerors. People aren't given a choice when they want to be ruled or to be subjugated to second class citizens, that happens when conquerors or empires decide to do so.