Residents in a small boat in the flooded region.

Video. WATCH: Dam blast adds to misery in Ukraine

Authorities rushed to rescue hundreds of people stranded on rooftops and supply drinking water to areas flooded by a collapsed dam in southern Ukraine on Wednesday, in a growing humanitarian and ecological disaster.

Authorities rushed to rescue hundreds of people stranded on rooftops and supply drinking water to areas flooded by a collapsed dam in southern Ukraine on Wednesday, in a growing humanitarian and ecological disaster.

It's clear that tens of thousands of people have been deprived of drinking water, many are homeless, crops are ruined, land mines have been displaced, and the stage is set for long-term electricity shortages.

Some residents of Russia-occupied areas hit by high water complained that help was slow in arriving, with some stranded on roofs and streets passable only by boat in scenes more like natural disasters than wars. Others refused to leave.

Latest video