Thousands of homes and businesses in Derbyshire were left without power overnight after an explosion at an electrical substation.
The station at Winster, near Matlock, was damaged on Wednesday afternoon and more than 30,000 properties in Matlock, Darley Dale and Cromford were affected.
By Thursday morning about 5,000 customers were still without power but this was restored by about 16:00 BST.
Western Power Distribution said it was investigating the cause of the blast.
