Why my OnTriggerEnter2D is not working?

I’m trying to destroy an barel if it hits the ground but it’s not working here’s my code:

using UnityEngine;
using System.Collections;

public class Rocket : MonoBehaviour

void OnTriggerEnter2D (Collider2D col) 
{
	if(col.gameObject.tag == "Ground") //if hit the ground explode... there's two layers "ground" and "nottriggerground"
	{				
		Destroy (gameObject);
	}
	
}

The barrel will roll on a floor and fall into another and then will explode…

But to roll the barrel must be on the ground and if the barrel hit the ground it will explode … Thinking about it I decided to create a layer for each floor.

My barrel will then roll on the floor X and will not explode… when it lands on the ground Y it will explode…

I also wanted to add particles, before being destroyed barrel shows BOOOM particles and then destroy.

[34588-sem+título.jpg|34588]

Check “Is trigger” in your collider to true.