k-means clustering or classification?
Choosing k=2 because you want to find classes "dead" and "alive" does usually not work. That is a common toy approach that barely works on exercise data such as the Iris data set.

Because k-means is unsupervised, there is no guarantee that for k=2 it will find dead/alive. It may as well find male/female (k=2) or Chuck Norris/everybody else (k=2).