back in chicago, ed ballinger was trying to send out warnings. messages. ything he could to try and save his planes. >> all i knew is that there was trouble and i wanted to warn everybody. >> one of those flights, ballinger tried to warn, are the airline's version of an e-mail. united flight 93. >> and i was sending out messages, one after the other. i think i sent 123 messages in a short time, an hour or two, i don't know what it was. i was screaming on the keyboard. i don't want to get the captain excited. i just sent him a discreet message. can i be of assistance? can i help you? and, at that time, the huge cbs that we had came on with cnn. >> this just in, you're looking at an obviously very disturbing live shot there. >> and i saw the secondary plnen which i didn't know at my time was the second tower. and i thought there was a succinct method with doing it with the least amount of words. beware, cockpit intrusion. before i got that one off, 93 called up and said that had a little turbulence. >> so at that point, it was routine. >> so you're sending ou

. >> reporter: for six years, ed ballinger has been sailing away from his memories. >> okay, that's gooder: his refuge? this boat named "the great old broad" where he's been afloat with his wife trying to escape the memory of a few brief words -- beware cockpit intrusion. >> said lock the so and so door. so i said hijacking alert. hijacking. sure they said possible hijacking. >> reporter: ballinger is footnote 69. ten years ago on september 11th, he was a dispatcher for united airlines in chicago, handling 16 flights leaving the east coast and heading west, including united's flights 175 out of boston and 93 from newark. >> first indication i had of 175 was on the stewardess on board called in her contact which was the maintenance center that they were hijacked. >> reporter: in united airlines san francisco maintenance office, supervisor rich bellamy was working one last day before leaving the airline for a new job. >> i was kind of looking around the room, drinking my coffee, realizing it was my last day, kind of bittersweet. and i heard a commotion -- or someone talking about something