This was a night incendiary mission involving 29 planes from the 6th Bomb Group:
Yokkaichi was next on the list of secondary industrial cities scheduled for the same incendiary raids which had virtually eliminated large cities such as Tokyo as B-29 targets. The city of Yokkaichi, lying twenty miles southwest of Nagoya, was attacked on the night of 17-18 June with twenty-nine planes bombing individually and dropping a total of 231 tons of incendiaries. Enemy opposition was negligible with no fighter attacks and anti-aircraft fire from automatic weapons only. Photographs later showed 59 per cent of the city’s built-up area burned out by 313th Wing raiders.
[Pirate’s Log, p. 47]
20th AF Mission 209