National Transportation Safety Board Chairman Deborah Hersman briefing reporters about the July 2013 crash of Asiana Airlines Flight 214 in San Francisco. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Passengers move away from Asiana Airlines Flight 214 on Saturday in San Francisco. This photo was taken by a passenger. Eugene Anthony Rah/Reuters/Landov hide caption

itoggle caption Eugene Anthony Rah/Reuters/Landov