"Police say there's evidence Canada train was tampered with."

And here's the highest-rated comment at the link:

Not to go off on some "conspiracy "deal but, Speaking as an experienced[heavy duty] mechanic, this cant happen, the "maxi-brakes" don't need air to stay on, they need air to release,,something does not compute with this,.Even if the engine was still running?, these type of brakes cant!! "self release", someone has to push the "maxi button" to make them come off,...and crude is not,in general, "explosive" per se,.. unless there are lots of fumes present[unlikely in a fully loaded car],..methinks there is more to this than meets the eye and I for one, am glad that this is being investigated etc,..Condolences to those who have experienced losses,.. we! are thinking of you all,..I know, it is not much, but it is good in the whole,,

Here's my post from yesterday observing the motivation for sabotage.