I recall it was hell to find any meaningful information after the wreck.
Probly still is.
My first reaction was What????- bottling the air has been known as dangerous since ca 1900.
So I looked at rulebooks, and all were the same
Set the air
Set what seems like a sufficient number of hand brakes
Release the air and pull
If the train moves. set more handbrakes, repeat. atc until nothing moves.
Finally it was revealed that all that had been done, but without releasing the locomotive brake, just the train brakes.
The fireladdies took care of the rest.
So how many politicians have said PTC would have prevented this...