The heavy, wet snow snapped tree limbs all over western New York, leaving some 392,000 homes and businesses without power.
A state of emergency was in effect across the region, banning all non-essential travel.
Branches and power lines lay draped across cars and houses, and normally busy downtown streets were still, blanketed by up to 60 centimetres of snow.
The snow, delivered in a fury of thunder and lightning, blanketed Buffalo and surrounding areas.
A 170-kilometre stretch of the New York State Thruway road was closed for hours, and food and water had to be delivered by snowmobile to stranded motorists until roads reopened.
Erie County authorities said two people died in traffic accidents, and one person died after being hit by a falling tree limb while shovelling snow.
It was the snowiest October day in Buffalo in the weather service's 137-year history.