WASHINGTON — The chief organizer of the Rio de Janeiro Olympics says security is his top concern, well ahead of the Zika virus. Sidney Levy, CEO of the Rio Organizing Committee, said Tuesday that keeping athletes and visitors safe from terrorism and other crime is his No. 1 top priority. He called the biggest fear “lone wolf” attackers. “Differently from Zika, security’s at the top of my list — the very top of my list,” Levy said at a Council of the Americas event.