Hi - the photos wouldn't disappear if they were stored on the phone. Were the photos stored on an external micro SD card - might have fallen out at the time the phone fell...
Can you connect the phone up to a computer & search through the folder structure?
To back up photos as you take them, install the Dropbox app on the phone, create an account - and you can set it that everytime you are on WiFi it will upload any newly created photos onto Dropbox for you. (this will only work on smartphones)