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.

A powerful storm downed trees and power lines, leaving more than a half million customers in Pennsylvania, Ohio and neighboring states in the dark on Wednesday morning, with local officials

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