Well nooby,
There arme some accidents due to different mechanical failures, like
Failing tailrotorblade
Wireing chaffed caused smoke in the cockpit
Blade Tip Cap Detached in flight
Forced landing into field after loss of power
Heavy landing due to tail rotor driveshaft failure
Tail rotor failure, followed by gearbox failure
So there are possibilities for mechanical failures, even so the chances are slim...