CBS quote: plane on the runway at a Florida airport???

What is the story behind the former NTSB guy's quote on the CBS evening news
report that "We know that two of the 9-11 terrorists left a plane on the runway at a Florida airport."
I don't remember hearing anything about this.

It sounds rather odd, and largely irrelevant as to whether we need tighter security at GA airports.
Max T, CFI

I don't know if there were two of them in the plane, but Atta did this at
Miami... I think maybe at Miami International, but I'm not sure.

In any event, there were two students in the plane, and they were doing some
training. One student would fly for a while, and then they would switch.
They were on a taxiway when something went wrong with the aircraft. I don't
remember what. But instead of taxiing back to the FBO, or even just calling
the tower to say that they were having trouble, they shut down (maybe the
engine had already quit on the them, I don't remember), left the plane on
the taxiway, and walked to a payphone to call their flight school.