Thanks, glad I asked.
I was scrubbing the ground control tape, the brake fire reporting aircraft was back on tower. I think the controller was working both freqs at the time.
AX4751 reported a brake fire on the right, number 2 side of the CRJ on F then said it's not a brake fire at all, looks like fire dumping out of the APU or engine compartment.
You can hear the initial fire report at about 18:25 into this clip:
http://archive-server.liveatc.net/kd...2017-2000Z.mp3