Help with respawning gameobject

Unity Engine
1

So I am creating a 2d platformer, and currently I am attempting to get a script to respawn the character when he falls of a platform. I have a box collider below and when the character passes through he is supposed to respawn at (0,0,0), but nothing is happening.

using UnityEngine;
using System.Collections;

public class DeathDetection : MonoBehaviour {

	public GameObject player;

	private void OnTriggerEnter(Collider collider){
		if (collider.tag == "Player") {
			player.transform.position = Vector3.zero;
		}
		else {
		 	Destroy(collider.gameObject);        
		}
	}
}
2

When I jump off a platform and fall through the collider the player just keeps falling, but other objects disappear

3

Anyone? Please could use some help