Milwaukee, WI—Tens of thousands of residents of a northern Wisconsin city were cleared to return to their homes on Friday, the day after a blast at a Husky Energy Inc refinery injured at least 15 people, a local official said.
Investigators searched for the cause of the massive Thursday morning explosion at the refinery, capable of processing up to 38,000 barrels of oil a day, which shook the city of Superior, Wisconsin, home to about 27,000 people.
