Power Returns to Most Areas Hit by Blackout Power has returned through most of the U.S. Northeast and Midwest and southern Canada -- the region affected by a blackout that directly affected at least 50 million people. Officials hope lighter demand over the weekend will help stabilize the system. Assorted problems with water and trash persist in some areas. Engineers are still trying to pinpoint the cause of the failure. NPR's Corey Flintoff reports.