The Regina Cyclone is the popular name for a tornado that devastated the city Regina, Saskatchewan, Canada on June 30, 1912, around 4:45 p.m. when two green funnel clouds formed to the south of city and tore a swathe through the residential area between Wascana Lake and Victoria Avenue and the downtown business district. It remains the deadliest tornado in Canadian history.
Damage from the tornado is estimated to be F4 on the Fujita scale. The tornado killed 28 people, injured hundreds, and left 2,500 people homeless. Around 500 buildings were destroyed or damaged; property damage was quantified at C$1.2 million and it would be forty years before the private and public debt incurred to rebuild and repair was repaid.
The tornado started 18 kilometres (11 mi) south of the city and continued for another 12 kilometres (7.5 mi) north before dissipating. It was 12 blocks long and 3 blocks wide. The worst damage was in the central business district, with many buildings entirely destroyed; the affluent residential area to the south was substantially diminished, but the tornado left houses untouched here and there immediately adjacent to houses which were flattened.
Debris was cleaned up quickly and the only remaining "souvenir" of this event are different-coloured bricks on the north wall of Regina's Knox-Metropolitan United Church, showing where the wall collapsed and was rebuilt.
The city charged those rendered homeless by the disaster nightly for cots set up in schools and city parks. They also charged homeowners for the removal of rubble from their homes.
British actor William Henry Pratt was appearing in a play in Regina at the time of the storm. In the aftermath, he volunteered as a rescue worker. Years later, he would move to Hollywood and change his name to Boris Karloff. In the 1960s, Karloff appeared on the talk and game show Front Page Challenge where he was featured not because of his notoriety in horror films, but because of his involvement in the Regina Cyclone of 1912.