[DManA]

The train was parked overnight and left unattended with one engine running that maintained the brake air pressure line.

I thought the great innovation 10 years ago was that air pressure held the breaks OPEN, and if the pressure failed they would CLOSE.

Did we forget this wisdom?

[DManA]

Sorry 100 years ago.

[thackney]

The reserve tanks on each individual car still closes and holds the brakes. Which is why the train did not start rolling for more than an hour.

The tanks are designed to give the operators time to set the hand breaks.

But the train was left abandoned, and procedure was not followed setting sufficient hand breaks prior to leaving unattended.