Heavy oils generally don't readily ignite due to their high flash point. But, if you sufficiently heat any oil based product the gases are generally extremely volatile. If it is also in a restricted container, now you have the possibility of a BLEVE.

I think there are some valid points that must be fully researched.

1. Is Bakken crude actually more volatile than crude oil historically moved by rail?

2. Are the additives from fracking or other processes a contributing factor or increasing risk of corrosion? Maybe fracking is causing more diluted gases to be in the crude?

3. There needs to be a discussion as to whether the unlimited movement of entire unit trains of crude, ethanol, and other hazardous material is theoretically a greater hazard due to the probability of many cars becoming involved in a major derailment versus groups of 5-10 cars in a general freight train.

No doubt the refineries are already well aware of what Bakken crude contains as they have to deal with it during the refining process.

I guess Bakken crude is just too rude ..