IPhone works but screen doesn't (still touch responsive)?

Okay, so I threw my iPhone 4s while it was wearing an otter box, so it didn't break, tho now, system sounds will still work, but the screen won't. I turned on "voice-over" by triple tapping the home button, and to my surprise, I could somewhat use the phone by listening to the voice-over assistant. There was a little dent in the side of the screen where I could slightly see into the phone, and I could see a little light when I "turned on the screen" (still wasn't working). Any ideas on what might have happened? I'm thinking that the screen connector may have come loose or something, since there's very little physical damage to the phone, and is fully functional aside from the screen not turning on.

You can contact otter box and tell them your phone broke while it was in their case. It was your fault that you threw it, but it should have protected it. If they are nice like the Life Proof case company, they might replace your phone for you.