Before Any action was taken, I would hope they got to learn about people such as Helen Keller. There are some notable blind/deaf people who have gone on to do some amazing things.
I mean if you want to die you want to die, but try not to die in ignorance. People forget about how hectic life was for early man: Gnawing on bones.. women dieing of childbirth at an alarming rate, Running away from giant predators.
I do not mean to be overly critical of there decision.. it is a scary notion living without sight and hearing, but why not try it first before you give up?