End Game when hit's water

I am making game that is basically a maze, but the huge thing I need, the last part, is to end the game when the First Person Character hit's the water at the end of the maze, or, if the time runs out. This is the time script I am using.

private var startTime;
private var restSeconds : int;
private var roundedRestSeconds : int;
private var displaySeconds : int;
private var displayMinutes : int;

var countDownSeconds : int;

function Awake() {
    startTime = Time.time;

function OnGUI () {
    //make sure that your time is based on when this script was first called
    //instead of when your game started
    var guiTime = Time.time - startTime;

    restSeconds = countDownSeconds - (guiTime);

    //display messages or whatever here -->do stuff based on your timer
    if (restSeconds == 60) {
        print ("One Minute Left");
    if (restSeconds == 0) {
        print ("Time is Over");
        //do stuff here
    //display the timer
    roundedRestSeconds = Mathf.CeilToInt(restSeconds);
    displaySeconds = roundedRestSeconds % 60;
    displayMinutes = roundedRestSeconds / 60; 

    text = String.Format ("{0:00}:{1:00}", displayMinutes, displaySeconds); 
    GUI.Label (Rect (43, 10, 100, 90), text);

Similarly to diabloroxx, you could have something like:

function OnCollisionEnter(other : Collision) {
    if(other.gameObject.tag == "Player") {
        //end game here

And put this code on a trigger collider that takes up the space of the water. For more on triggers go to http://unity3d.com/support/documentation/Components/class-BoxCollider.html and scroll down to triggers. You can end the game by sending the player to the title screen or something, but I'm not sure if that is what you want. Just make a scene used as the title or end game screen and swap to that scene.

You can use the FPS tutorial posted here : http://unity3d.com/support/resources/tutorials/fpstutorial

The game has a destroy tag attached to the player when he falls into the water. You can duplicate the scenario in your game.