erm, you could make 3 triggers, radius 50*50
in the condition put: this AND timeout
in the activation, put
"_x setdammage 1" foreach thislist; starttimer = true
name each trigger t1, t2, t3
in the script, right after you spawn the bombs, put this:
t1 setpos getpos (name of first bomb)
t2 setpos getpos (name of first bomb)
t3 setpos getpos (name of first bomb)
thisll place triggers where the bombs blew up.
now you gotta make it so teh triggers stop killing peopel after a while...
make a new trigger, radius 0*0
make condition: starttimer
make countdown however long after the napalm you want peopel to die
in activation: starttimer = false
now make another trigger, make the activation: nobody present
in the activation field, put starttimer = true
this is just a basic summary of how to do this, there are more advanced ways, but this is the most practical.
be wary though, due to limitations in the "thislist" command, it takes time for everyone in the radius to die (one or two people die at a time, so there is a very short delay between peeps dying)