At the time, I was working as the producer for a morning radio-talk show in the town where I live. I had the control room TV tuned to the Weather Channel, and thus while the first plane went in shortly before 9:00am, the host and I were doing our usual end-of-show chit-chat on the air. We ended the show, I played a commercial and a station-ID, and went into the CBS Radio News at the top of the hour just in time to hear the breaking news that "a small plane has just crashed into one of the twin towers of the World Trade Center in New York." I lunged for the remote control and switched the TV to CNN while I listened to the radio report.
There are several radios scattered around the building that are all tuned to our station, so all the early-birds in the building heard the news and converged on the control room.
Then the second plane hit.
At that point, I had less than 2 minutes before the 9:06am health show started, and the next host wanted to know what we were doing. I told him to go ahead and start his show like normal, but to be ready to go to a break at a moment's notice. In the meantime, we started trying to get ahold of the General Manager. The next show started at 9:06am as-scheduled, but by 9:10am the GM had called back and told us to go into breaking-news mode. I signalled the host to break, then put on the CBS breaking news feed, threw together an automation program to break in with quick liners and station IDs every few minutes, and then sat back and watched everything unfold for the rest of the morning, right there in the control room at the radio station. The anger and helplessness I felt that day was unreal.
Early in the afternoon I got to go home for a break for a few hours, but I had to come back in later that night to man the control room again. I was there from 6pm to about midnight, and I was the only one in the building, and those were the lonliest 6 hours of my life.