It must have been pilot error if they flew into a mountain on a *published* IAP.
A friend of mine did it though, with radar cover, and they all died. Controllers will obviously warn if they notice that there is a problem but often they are busy elsewhere and it is the pilot's responsibility. You'd be better off with GPS and a TAWS funtion, in that case I am 100% sure my friend and his passengers would be alive today (they messed up, meant to go Missed at the MAP in IMC but for some reason just carried on flying S&L straight into a mountain - had they been 15 feet higher they would have missed).