The Amritsar massacre, says Wikipedia, took place in the Jallianwala Bagh public garden in the northern Indian city of Amritsar, and was ordered by Brigadier-General Reginald E.H. Dyer.
On Sunday 13 April 1919, Dyer was convinced that a major insurrection was at hand. He banned all meetings, and hearing a meeting of 15,000 to 20,000 people had assembled he marched his fifty riflemen to a raised bank and ordered them to shoot at the crowd which included men, women, and children. Dyer kept the firing up for about ten minutes.
Official Government of India sources estimated the fatalities at 379, with 1,100 wounded. The casualty number estimated by the Indian National Congress was more than 1,500, with approximately 1,000 killed.[1]
Dyer was removed from duty and forced to retire, but he became a celebrated hero in Britain among people with connections to the British Raj.