Zanne,
Just what are you asking in this technical support forum?
The glass on the iPhone is actually quite durable, however, depending on how the phone is dropped, onto what surface it falls, it can break. It's never been billed as being break-free. I've dropped my phone multiple times, I don't have a case, and while the backing of my iPhone is pretty scratched, the glass is pristine. Go figure.
In any case, an accident is an accident and Apple will not cover this. You will have to have it repaired, and the repair fee is quite hefty, probably around 200.00, but you won't have to buy a whole new phone if it's just the glass that needs repair.
If you paid for your phone with a credit card, you might be covered for accidental damage, so you should check out that option.