call for help but a warning. The exact time at which Flight93 came under the hijackers' control cannot be determined. Officials believe that at 09:28, the hijackers killed Mark Rothenberg, assaulted the cockpit, and moved the passengers to the rear of the plane at the same time to minimize any chance that either the crew or the passengers would interfere with the attack. The other hijacked flights were taken by five-man teams, but Flight93 had only four hijackers, leading to speculation of a possible 20th hijacker. The 9/11 Commission believed that Mohammed al-Qahtani was the likely candidate for this role, but was unable to participate as he had been denied entry into the United States one month earlier. With many passengers saying in phone calls that they saw only three hijackers, the 9/11 Commission believed Jarrah remained seated until after the cockpit was seized and passengers were moved to the back of the aircraft and then took over the flight controls out of sight of the passengers. The cockpit voice recorder began recording the final thirty minutes of Flight93 at 09:31:57. At this moment, it recorded Jarrah announcing, "Ladies and gentlemen: here the captain. Please sit down, keep remaining seating. We have a bomb on board. So sit." The commission believed Jarrah tried to make an announcement to the passengers, but pressed the wrong button, sending the message to Cleveland controllers; Mohamed Atta had made the same error on Flight 11. The controller understood the transmission, but responded, "Calling Cleveland center, you're unreadable. Say again, slowly." The flight recordings indicate that a wounded man, believed to be Dahl, was moaning in the cockpit. The man pleaded, "No more," or "No," repeatedly, as the hijackers shouted for him to sit down and to stop touching something. Sandy believes that Dahl took actions to interfere with the hijackers, including possibly disengaging the autopilot, and rerouting the plane's radio frequency so that Jarrah's attempts to communicate with the passengers were instead transmitted to air traffic controllers. A woman, thought to be first-class flight attendant Debbie Welsh, is heard being held captive in the background and is heard struggling with the hijackers and pleading, "Please, please, don't hurt me." Jarrah instructed the autopilot to turn the plane and head east at 09:35:09. The aircraft ascended to and air traffic controllers immediately moved several aircraft out of Flight93's flightpath. The woman in the cockpit is