Four heavily armed men walked into a Seattle Starbucks last Wednesday and ... what? Robbed the place? Shot somebody?
No, they ordered beverages. Perhaps lattes with little swirls of whipped cream on top, although that's not specified in The Wall Street Journal story about the event, or incident, or whatever it was.
The men were trying to make a point, that more people should openly wear sidearms in public places. They are part of a movement called "open carry," and they argue that we'll all be safer when we all carry guns.
Now…say an old lady with a pre-existing heart condition, sitting at a table having coffee, sees these heavily armed men coming through the door, gets terribly scared thinking the worst; has a heart attack and dies…
...well we can bet there will be a wrongful death action in the offing.
Basically, liability for the aggravation of a pre-existing condition, can attach along these lines
The negligent party may be liable for the resulting harm to another even though a physical condition of the other, which is unforeseeable (i.e., neither known nor should be known) to the negligent party, makes the injury greater than that which the negligent party (as a reasonable person), should have foreseen as a probable result of his or her conduct.
Thus, even though a person incurred greater injuries due to his or her preexisting condition, the negligent party is liable for such injuries. This rule makes negligent tortfeasor liable for the aggravation of pre-existing injuries aggravated by said tortfeasor’s acts or omissions. Such rule applies to tortuous negligence, intentional acts, or strict liability.
In other words, “you take the plaintiff victim as you find him or her.”