The Cairo fire (Arabic: حريق القاهرة‎), also known as Black Saturday, was a series of riots that took place on 26 January 1952, marked by the burning and looting of some 750 buildings—retail shops, cafes, cinemas, hotels, restaurants, theatres, nightclubs, and the city's Opera House—in downtown Cairo. The direct trigger of the riots was the killing by British occupation troops of 50 Egyptian auxiliary policemen in the city of Ismaïlia in a massacre one day earlier. The spontaneous anti-British protests that followed these deaths were quickly seized upon by organized elements in the crowd, who burned and ransacked large sectors of Cairo amidst the unexplained absence of security forces. The fire is thought by some to have signalled the end of the Kingdom of Egypt. The perpetrators of the Ca