The water should be directed to your drain if it was built correctly, but who knows if it was or not. A membrane is supposed to be installed underneath the tiling to keep the water from leaking through. Here are a couple of links to show you examples of how a pan is made, there are many variations so yours could be different.
http://www.leakyshower.com/ARTICLE%2...r%20Floors.htm
http://leakyshower.com/shwrpncn.htm