^ Name says it all how do I do it?

Create a trigger volume around the area you want people to spontaneously die in. Name it something. We'll come back to that name. Then, create the script:

(global short plyrnum 0)

(script continuous nonrecursivescript
	(if 
		(= plyrnum 15)
		(begin
			(set plyrnum 0)
		)
		(begin
			(set plyrnum (+ plyrnum 1))
		)
	)
)

(script continuous kill
	(if
		(volume_test_object [TVOL] (list_get (players) plyrnum))
		(begin
			(unit_kill (unit (list_get (players) plyrnum)))
		)
	)
)

Replace [TVOL] with the name of your trigger volume.

Helpful tip: Don't add the [].