I'm sure this answer isn't going to please some of you and it's certainly not convenient for the displaced passengers, however, here it is;
Force Majeure Event This information can be found under "Terms of Transportation" at the bottom of the page on the Amtrak website. Obviously, anyone can then purchase a ticket on the next train if there is space available. In this particular instance, #28(15) was fully booked so an extra coach was added to accommodate any passengers from the train that returned to Portland with all the passengers which was #28(14). Unfortunately, if you previously had a sleeper, there were only two or three rooms still available on the 15th.