To clear up some points, just because track is 'old' doesn't mean it is bad. The web of the track is still good on most of that stuff and I don't believe a broken rail was the cause for this wreck. Seen rail used from 1900's before (Not mainline I'll give you that)
Also, there was no half-a$$ing of the work done up there this summer, believe me those crews did good work given the amount of time they had to do it.
Consider that FRA inspectors have been on the line (Whether you have seen them or not, trust me they've been there) multiple times before, during and after work done. Lastly, look at recent weather conditions, rain, rain, rain, and rain. My friends, this adds up to a classic case of ground movement under the roadbed. Factoring in the forces of moving the loads at the speed it is at (<10MPH), I'm going to highly doubt it was a broken rail (Aftermath pics may show broken rails but that is the result of the derailment, not the cause). While I'm not saying it couldn't have been a broken rail, I highly doubt it was. And oh yeah, they have been running track cars everyday on all the lines to look for things like this. Once again, I'm going to put my money on shifting ground under the roadbed, which regardless of track condition you really can't do much about (Maybe a culvert).
Sorry if I come off as defensive, but the claim that this is from deferred maintenance doesn't jive with me here. Considering the number of inspections done weekly by Pan Am crews and inspections done by the FRA this year, as well as the work they put in this summer, I don't believe it was the cause. Its possible a fractured rail web caused this derailment, but given the looming spring conditions, I'm gonna say that wasn't it.
Also howabout this, lets create a simple safety ratio of crude oil trains on Pan Am thus far.... Let's assume they have run 12 a month since September, and 4 a month from April to end of August. Then, let's assume that each train is average 90 cars (Some have been 100, some 80).
12x6 = 70
4x5 = 20
Approximately 90 trains x 90 cars = 8100 crude oil car loads since inception. Now divid 8100 by 15 (cars derailed today) = .00185 and subtract that from 1 = .99815 or a 99.815% safe handling rate since inception. Compare this to the industry average of 99.997 % and also factor in the amount of hazardous spillage was here (3 gallons). Not saying they dodged a bullet, I'm saying they have been operating safely and doing a good job of preventing accidents on par with industry standards.