I would want a gun, a knife, mace, taser, hand held stunner, expanding baton, hair spray, fish net, ANYTHING THAT COULD H AVE BEEN USED AGAINST THAT FOOL. Having a weapon doesn't mean anything, you don't have to use it, but not having one or having no skills limits your chances of staying safe.
What we are specifically talking about here, now, was a relatively open space, one belligerent, and plenty of people who could have helped.
Unless I'm mistaken, these men tried to talk him down and the torqued up nutcase used a knife to kill these unarmed men.
He was crazy, aggressive, out of control. That made him vulnerable to a brutal, no holds barred attack. All you had to do was out think him and get past his weapon.
In the exact scenario that I expect happened, there were people in front of him, behind him as well. A strong man who knew how to cause injury, with or without a weapon, would have been in a position to stop that threat as soon as it turned violent if he wasn't the immediate focus.
Now that we have specifically addressed one nut with a knife in a locked train car, does the run for cover and save yourself argument hold water? In that specific situation, everyone was vulnerable to dying. There was no cover. No escape.
I would love to carry a full compliment of weapons, even an old medieval flanged mace. Draw whatever you have, use whatever skills you have, stop that threat before you're the only one left alive.
I genuinely expect that the people on that train couldn't even toss a possum out of the outhouse.