A powerful nor’easter slammed the U.S. Northeast on Saturday, unleashing strong winds, heavy rain and dangerous coastal waves as the storm left roughly 100,000 customers without power and claimed at least one life.

The New York City Housing Authority confirmed that one of its employees was killed by a falling tree in Brooklyn as the storm swept through the city. Across the Mid-Atlantic and New England, emergency crews worked to restore electricity after high winds toppled trees and damaged power lines.

The slow-moving storm was expected to continue threatening tens of millions of people on Sunday, with coastal communities facing the risk of significant flooding as the nor’easter churned along the Eastern Seaboard.