The first nationwide oil refinery strike in more than 30 years was expected to grow by four more plants over the weekend, including the largest refinery in the U.S., the Motiva Enterprises refinery in Port Arthur, Texas. The United Steelworkers union said Saturday workers at the Motiva Enterprises refinery started their strike at midnight Friday. Employees at two other refineries and a chemical plant in Louisiana planned to strike at the end of Saturday. The union said in a statement that it expanded the strike that started Feb. 1 at refineries largely in Texas and California because the industry has...