As someone who works in the electric power industry, I can tell you that defending actions like this is very difficult. If it can be shown that any signage was missing or did not meet the present standards, a defendant can be held liable. If a train was parked in an unusual spot, or power was left on that is normally cut off, it can add to the problems. In addition the plaintiff's often very tragic physical and mental injuries creates sympathy with jurors. Amtrak will not have an easy time. The issue is not whether the person was right or wrong or trespassed or did not trespassed. It is whether the defendant's negligence contributed to the extreme consequences of the plaintiff's stupid actions. Defense in not impossible, but it is not a cakewalk either.
If everything is in order, you have a chance to win. If not, you settle, or go to trial and hope for the best. Like it or not, that is the way it is.