Sections of track are in the process of being replaced
Uninformed speculation to the contrary, track is most likely culprit. A soft spot under the ballast, a few rotten ties, spreading of the rails on the curve. People looking for spectacular causes are likely to be disappointed. Simple things like these generally end up being the cause. SDC doesn't enjoy teh sophisticated methods Class I RRs use to detect these things, and THEY DON"T NEED THEM. Speeds are so low as to already qualify under the strictest kinds of slow orders. Loads are laughably small in relation to what real narrow gauge mining roads carried. The equipment is, the gag spiel notwithstanding, as up-to-date as can be expected.
The simple fact is, the excrement sometimes impacts the rotary air circulation device through no fault. A pox on all ambulance chasers and their jackdaw clients! And, no, had my family been on that train, we would not being suing or joining in any other suit. it is purely greed, and the tort laws in this country need serious and sweeping reform.