Niagara Falls partially freezes as deadly polar vortex hits the Northeast after blasting the Midwest with record-breaking -30F temperatures and leaving at least 21 dead (9 Pics)

Breathtaking photos show Niagara Falls partially frozen by the polar vortex that has blasted the Midwest
Tourists observed large chunks of ice flowing over the tremendous volume of water on Thursday
And though some photos show what looks like frozen Falls, the water actually never stops flowing underneath
The Niagara Falls winter wonderland was caused by the polar vortex that is taking aim at the Northeast
At least 21 people have died as record-breaking low temperatures wreaked havoc across the Midwest
Painfully cold weather system that put much of the Midwest into a historic deep freeze lingered on Thursday
Plunging temperatures continued to break historic records for a second day with lows of negative 38F
At its worst, the cold snap caused temperatures to plunge to -42F on Wednesday across the Midwest
Cold settled in over the Northeast with Massachusetts, New York and Pennsylvania experiencing bitter temps