Buenaventura Durruti

Buenaventura Durruti was a pivotal figure in Spanish anarchism during the Spanish Civil War. He fought for the Confederación Nacional del Trabajo, with the fighting he took part in largely localised to Madrid. In particular, he hated communists. Durruti was mortally wounded in battle by friendly fire. At the time, it was believed by many, including the dying Durruti, that he had been shot by a sniper. He died two days later in the Ritz Hotel, Madrid. (PROSE: History 101)

Behind the scenes
In reality, Buenaventura Durruti was indeed killed by friendly fire. At the time, the story of him being killed by a sniper was reported to boost the morale of soldiers.