Additionally , the Tōnankai earthquake occurred in December 1944 with the aircraft factories and prototypes badly damaged as a result . On 9 June 1945 the airstrikes on Aichi Kokuki and Aichi Tokei Denki Seizo Co. , Ltd blew up the S1A first prototype and forced movement of the second to the Gifu large Sadakazu factory to be assembled , but on 9 July another airstrike destroyed the second prototype . To date the Aichi S1A is still the most massive fighter developed in Japan 's naval history
Tōnankai earthquake
1944 Tōnankai earthquake
Aichi S1A