The Japan Association for the 2025 World Exposition resumed the Osaka–Kansai Expo’s signature water show on 11 July after a 37-day suspension caused by excessive levels of Legionella bacteria. Water samples taken on 4 June showed concentrations roughly 20 times above national safety guidelines, prompting the closure of the Water Plaza attraction and part of the adjacent “Silent Forest” zone. Subsequent inspections confirmed that the bacteria levels have fallen below the guideline value following the installation of additional circulation pumps, intensified disinfection and a more frequent testing regime. With the measures in place, authorities cleared the daily “Water and Air Symphony” performances to return at midday and in the evening. Expo organizers said they will maintain the enhanced monitoring program throughout the summer to prevent a recurrence and ensure visitor safety as attendance builds ahead of the event’s peak months.