Ukraine's troops long planned their move on Russian forces. Then came the flood

Streets are flooded in Kherson, Ukraine, on June 7, after the walls of the Kakhovka dam collapsed. Residents of southern Ukraine, some who spent the night on rooftops, braced for days of floodwaters on as authorities warned that the dam breach on the Dnipro River would continue to unleash water from a large reservoir. (Libkos/AP)

KHERSON, Ukraine — The soldiers had staked out the islands for months, working in shifts, often crossing the river at night to build a bridgehead for Ukraine's long-awaited counteroffensive.

"Then our command office said the enemy had blown up the Kakhovka dam," said Andriy, a tactician in a territorial defense unit in this southern Ukrainian region.