The Boston Massacre Study Guide summarizes key details of the historic event. It occurred on March 5th, 1770 in Boston, involving British soldiers, loyalist slaves, and patriot colonists who wanted independence. Tensions had been rising in Boston between soldiers and colonists. Crispus Attucks was the first to die after a soldier fired into the crowd, resulting in 5 total deaths. While tensions led to the event, it remains unknown which side fired the first shot.