The Great Kantō earthquake (関東大地震, Kantō dai-jishin; Kantō ō-jishin) struck the Kantō Plain on the main Japanese island of Honshū at 11:58:44 JST (02:58:44 UTC) on Saturday, September 1, 1923. Varied accounts indicate the duration of the earthquake was between four and ten minutes. Extensive firestorms and even a fire whirl added to the death toll. Civil unrest after the disaster (i.e., the Kantō Massacre) has been documented.