Major flooding from the destruction of a huge dam has devastated towns along the lower Dnieper River in Ukraine and forced many civilians to flee to rooftops, attics and higher ground. Ukrainian rescuers have been carrying out risky missions to evacuate civilians in small boats from the areas occupied by Russian forces on the river's west bank. The rescuers have come under fire from Russian snipers and drones. Now the window for escape is closing. Rescuers are increasingly cut off by mud as floodwaters decrease. And more Russian soldiers are returning and reasserting control. Accounts of Russian assistance vary. But many survivors accuse Russian authorities of doing little or nothing to help displaced residents.