Deadly Nor'easter's heavy rain and wind knocks out power to nearly 600,000

Massachusetts' governor expects a "multi-day" power restoration process.

Nearly 600,000 customers were without power in New England on Wednesday after a record-breaking nor'easter devastated the region.

Heavy rain flooded roads from Massachusetts to New York, while water rescues were reported in New Jersey.

Dangerous winds also toppled trees and blocked roads.

One person was killed in Morris Township, New Jersey, when a tree limb fell on two cars Wednesday morning, according to ABC New York station WABC.

A kayaker also was found dead off the coast of the Bronx, reported WABC. The 45-year-old man had headed out on the water Monday night, around when the storm started, en route from Long Island to Westchester County, New York.

The storm became a "bomb cyclone" when its pressure dropped 24 millibars in less than 24 hours. In Nantucket, Massachusetts, the nor'easter set a record for the lowest pressure ever recorded in October.

The heavy rain should be ending in most of the Northeast on Wednesday, but winds will continue to roar up to 60 mph from Long Island to Massachusetts to Maine. By 7 p.m., wind gusts could still reach near 50 mph in Massachusetts.

In Massachusetts, where about 500,000 customers remained without power Wednesday afternoon, Gov. Charlie Baker said he expects a "multi-day" restoration process.

ABC News' Victoria Arancio contributed to this report.