People ride the Goliath roller coaster, with a 255-foot drop, at Six Flags Magic Mountain in Valencia in 2021. (Mel Melcon / Los Angeles Times) Struggling with a plummeting stock price and a decline in revenues, Six Flags Entertainment Corp. named a new CEO Monday, weeks after company officials suggested they would sell more underperforming theme parks. Six Flags announced John Reilly, a veteran theme park operator, as its new president and CEO. He had served as an interim CEO and chief operating officer ...