Wikipedia:

The atomic bomb go game is a celebrated game of Go that was in progress when the first atomic bomb was dropped on Hiroshima, Japan on August 6, 1945. The venue of the game was in the suburbs of Hiroshima, about 5 kilometers (3.1 mi) from ground zero.^[3]

The game was about to enter its third and final day of play when the bomb dropped at 8.15 am. The players — Hashimoto Utaro, who was the Honinbo title holder, and Iwamoto Kaoru, who was the challenger — had replayed the game to the adjourned position but had not yet started to play on. The explosion caused disruption to the game, damage to the building, and some injuries to those attending the match. Play was resumed after the lunch break, and the game was played to a conclusion that evening. Hashimoto, holding White, won by five points.

Game 1 of the match had been played 23 to 25 July in the centre of Hiroshima. The move to further out of the city area was recommended by the police, after a drop of propaganda leaflets^{[citation needed]}.

The match was continued after the war, ending in a 3-3 draw. A three-game playoff was held in 1946, won by Iwamoto in two straight games to claim the Honinbo title (becoming Honinbo Kunwa). Utaro went on to reclaim the title in 1950.^[4]

The Honinbo title, originally the name of one of the Four go houses or state-funded academies of go that had been set up in the 17th century, had become the first of the annual titles for which professional players compete on the death of Honinbo Shusai. Wartime conditions had made the holding of annual matches problematic, since large preliminary qualifying tournaments were required to find a challenger. In 1945 the Honinbo Tournament was being run for the third time.

Pictured: Atomic Bomb Go Game at play 106, when the bomb exploded on Hiroshima.^[5]