Um....

You know, you both sound utterly paranoid.

We've already HAD "SHTF" situations in the USA, in many places, at many times, and the response has always been for Americans to come out and help.

Just a few years ago, right near me, an ice storm stranded a bunch of people on i78 for several days. Rather than a zombie apocalypse, what happened was locals on snowmobiles shuttled food and water and medicine to the folks stuck in vehicles.

In NYC, 2003, the lights went out. Millions of people - the dreaded "urban hordes" of so many overwrought imagined scenarios - slept outside, wandered the streets, made new friends and got home, eventually.

Bridges collapse in Minneapolis - the help rushes in. Floods come to the Red River, everyone fills sandbags.
San Francisco gets blasted with an earthquake, communities turn out in droves to do what it takes.

Yes, we've had riots in the USA, yes, they have been scary (I remember the Rodney King and Washington Heights riots) and they are localized, short-lived and really really rare.

If you're on a train, you're already near a lot of gear. There's first aid. There's water. There's radios and backup radios. There's people who are PAID to come rescue your ass on the way. Nobody is walking 40 miles in "enemy territory" and nobody is going to be abandoned to the wilderness if a crew car goes missing for 24 hours.