in another post, maybe sammy mentioned how easily the screen of smartphones break, so i found this videos with interesting torture test resultshttp://cnettv.cnet.com/samsung-galaxy-s3-torture-test-always/9742-1_53-50127632.html
she is using rice to absorb humidity from the phone, something controversial that might work with samsung phones, because they protect components with a resin around contacts of some components but i haven't seen a galaxy sIII disassembled so could be wrong
usually when you let a phone fill with water and it remains on with the battery placed, this is more likely to happen
and that happens alot in display connectors, internal connectors and headphone connectors, sometimes you can change the part but most times you can't
also found a drop test for lg galaxy nexus 4http://www.youtube.com/watch?feature=player_embedded&v=nlgG33n71m0#!
(Embedding disabled, limit reached)http://www.tomshardware.com/news/Nexus-4-Drop-Scratch-Drop-Test-Video,19181.html
i think that the problem with dropping your phone and breaking the screen is more a matter of luck, let it fall in the right height and the right angle, a corner seems to be what could make the screen break
last week i let fall my xperia mini and nothing happened but it wasn't high enough i think, also is just a 3" screen so smaller screen is more likely to survive to such event