The hijacking began at 09:28. By this time, Flights 11 and 175 had already crashed into the World Trade Center and Flight77 was within nine minutes of striking the Pentagon. The hijackers on those flights had waited no more than thirty minutes to commandeer the aircraft, most likely striking after the seat belt sign had been turned off and cabin service had begun. It is unknown why the hijackers on Flight93 waited 46 minutes to begin their assault. According to reports from passengers and crew, the hijackers tied red bandanas around their heads and sprang from their seats. At 9:28:05, as the flight cruised at 35,000 feet over eastern Ohio, the plane abruptly dropped 685 feet. At 09:28:17, eleven seconds into the descent, Cleveland heard a man scream into the cockpit radio: "Mayday! Mayday! Mayday!" A second raspy shout went, "Hey! Get out of here!" Cleveland Air Traffic Controller John Werth didn't know the source of the call he heard, and could only make out what he heard as "just some gruttural, gruttural sounds." He responded, "Somebody call Cleveland?", before he noticed Flight 93's rapid descent and heard at 09:28:50 another transmission from the cockpit, screams alongside an even more desperate and garbled refrain: "Hey! Get out of here! Get out of here!" The commission made no conclusion as to whether it was Dahl or co-pilot LeRoy Homer giving the distress call, but when Melody Homer and Sandy Dahl, Jason Dahl's wife, together listened to the tape, Melody Homer claimed to have recognised her husband’s voice as the man who was shouting. The flight dropped in half a minute before the hijackers stabilized the aircraft at 34,315 feet, and soon began climbing southeast. Of the four hijacked aircraft on 9/11, Flight93 was the only aircraft that broadcast a distress call. It is likely that because the pilots had been warned of the World Trade Center attacks and to beware of cockpit intrusion, when the hijackers attacked them, they purposely pressed on the talk button of the radio microphone, so sounds of the struggle in the cockpit will be heard by FAA ground controllers and by pilots of planes on the same radio frequency. Werth believed it was not just a call for help, but a warning as well. During the next two minutes, Werth made seven attempts to contact Flight 93, with no reply, while other controllers moved nearby flights out of the way.