We lost a chief same way on a deployment. He simply passed in his sleep. 5000 plus men like a small town some do pass on by heart attacks etc.
A few years ago I began hunting down some shipmates. Guess who I found? Alive and well. He told me what had happened. He did have some convalescent leave then got shore duty in the yards then later retired. He makes kids toys in his shop in Va Beach.
A heart attack by a senior enlisted especially on a carrier is not that uncommon.