SULLIVAN, Wis. — Utility crews are working to restore power to customers who lost service in a powerful storm that blew through Wisconsin.

More than 20,000 We Energies customers were left without service after winds of more than 50 mph caused power lines to go down. Only a fraction of those customers remained without power early Thursday.

The strong wind that accompanied driving rain also knocked down trees and caused part of a roof to collapse on a Walmart store in Lake Delton. Two employees suffered minor injuries.

Forecasters say some of the heaviest rain fell in Columbia and Dodge counties. Street flooding was reported in Portage and Pardeeville.