T in Oklahoma said:

"In "The Wreck of the Old 97", the words "lost his airbrakes" were misinterpreted as "lost his average." It is often heard with the latter words."

"Lost his airbrakes" makes no sense at all. A train's brakes are "deadman brakes"--that is, if you lose the air, the brakes come on; they are held off from application by the air. So unless you think that the application of brakes caused the accident, it wouldn't be "lost his airbrakes".

Dave Oesterreich