Нова Каховка, Новокаховська міська громада, Каховський район, Херсонська область, Україна
Ukrhydroenergo
Wikipedia[1] gives 6 June 2023 between 02:00 and 02:54 local time; UN-IHE[2], Al Jazeera[3] and the European Commission's civil protection office all date the breach to 6 June 2023.
The Kakhovka Dam on the Dnipro in Russian-held Kherson Oblast was breached in the early hours of 6 June 2023, emptying a huge reservoir and flooding dozens of settlements.