WARSAW, June 30, 2020 A sign warning people not to swim in the river is submerged in Warsaw, Poland, on June 30, 2020. Heavy downpours have caused flash floods in Warsaw on Monday evening, with over 300 cases of flooded cellars, garages, as well as underground stations and tunnels, having been reported. (Photo by Jaap Arriens/Xinhua) (Credit Image: © Xinhua via ZUMA Wire)