After two days of conflicting explanations, falling stock prices and worldwide outrage, United Airlines [part of United Continental] entered mea culpa mode Tuesday afternoon when its chief executive announced an internal investigation into an incident involving a man who was violently removed from a plane so a crew member could have his seat. “I continue to be disturbed by what happened,” United chief executive Oscar Munoz said in a statement. “I deeply apologize to the customer forcibly removed and to all the customers aboard. No one should ever be mistreated this way.” “We are going to fix what’s broken so this never happens again,” Munoz said, promising a public report by April 30 on a review into United’s partnerships with law enforcement, its policies on giving seats to employees and overbooking.