i've seen a total of two dozen Galaxy Centuras with shattered screens still working fine otherwise, (of course, with cheap pre-paid phones and abusive use, it's bound to happen) but when my GS3 got busted the entire screen was dead. didn't light up, didn't respond, nothing. i could only make use of it by using the S Voice hotword 'Hi Galaxy' to do anything like make a call or toggle wifi, or interface with my Galaxy Gear (which i've found is one handy watch. i often leave my phone in my pocket, protected because of it). other than that it was essentially useless. i never had one just up and shatter leaving the entire LCD dead. i have lost some earlier models (mostly cheap Net10 stuff) to shatters, screen was ok but no response to touch.
Granted the GS3 was tough. it survived being run over by a golf car at work, got in the mud another time, dropped countless times while shopping and only popping the battery out, being thrown against walls when i got angry with it for various reasons (the main one being the 'not connected to internet' when i had perfect 4G service) and even drooled on by deer. but that last time i fell on my tile floor, bam! screen completely dead and shattered. not lighting up nothing. worked other than that. got the GS4. Samsung can make a damn good phone. Just wish that for once i got lucky enough to still have a working touchscreen until i can really afford the replacement.