At least four people were killed in Pennsylvania on Tuesday and hundreds of thousands of customers were without power after severe weather that had torn across the High Plains and Upper Midwest earlier this week pushed into the Northeast and Canada.

Officials are reporting at least three deaths amid a storm system that downed trees and power lines and left about half a million customers in the dark across Pennsylvania, Ohio and neighboring states.

More than 200,000 customers remain without power in the Pittsburgh area after a storm brought tornado-level winds.