Numerous Indian citizens are hurt when an office building is attacked by the British. -- That sort of incident would cause Indian nationalism to increase in response.
As a historical note, I can point to an incident even more grievous than the suggested example. In 1919, in the Indian city of Amritsar, British troops (along with Nepalese Gurkha troops whom the British employed) killed over 300 Indian nationalists -- perhaps as many as 1,000 of them, in a public garden. (379 was the British government's official estimate. The Indian National Congress said that approximately 1,000 were killed.)
This "Amristar Massacre" occurred in the public space known as the Jallianwala Bagh. A large number of Indians had gathered there for a peaceful protest against how Britain had forced Indians to be enlisted as soldiers for war and against the war tax Britain had imposed on Indian citizens during World War I. The demonstration coincided with regular fairs held at the park, so there were thousands of people there. Because of concern over growing nationalist sentiment, Britain had placed Amristar under martial law and banned all gatherings in the city. But many of the fair-goers and those participating in the demonstration didn't know about this change in law. British Brigadier General Reginald Dyer, in command of the empire's forces in the area, ordered his troops to fire on the crowd to teach the Indians a lesson - to have a "moral effect" on them, as he later said. The killing of unarmed Indians by British troops only made the nationalist movement grow stronger. India had supported the British cause in World War I, hoping to gain partial autonomy in return. After the incident at Amristar, Indian nationalists determined that they needed to work toward full independence from Britain.
