sorry for double posting but, it doent crashes. Problem is that the impact event called over and over instantly, thus you are calling level_load too many times, this make engine crash.
function level_event(){
my.emask &= ~ENABLE_IMPACT;
ent_remove(me);
wait(-1);
my = NULL;
you = NULL;
level_load("level.wmb");
wait(2);
}
works fine.