Bomb not effecting anything.

Questions & Answers
1

I created a bomb, i want the bomb to effect the enemy health only if the bomb is in the enemy range. Codes:

1.When the bomb collides with any thing:

var e : GameObject;
var radius : float = 3.0;
var power : float = 300.0;
var damage : int = 100;

function OnCollisionEnter(c : Collision){
	
	var enemy : GameObject = GameObject.FindWithTag("Enemy");
	
	var explosionPos : Vector3 = transform.position;
	var colliders : Collider[] = Physics.OverlapSphere(explosionPos, radius);

	for(var hit : Collider in colliders){
	
	if(hit.gameObject.tag == "Player"){
		
		playerHealth.health -= 75;
		
	}
	if(hit.gameObject.tag == "Enemy"){
	print("work");
	yield WaitForSeconds(3);
	Destroy(gameObject);
	Instantiate(e, transform.position, transform.rotation);
	enemy.SendMessageUpwards("HitEnemy", 15, SendMessageOptions.DontRequireReceiver);
		}
	}
	
	if(c.gameObject.tag == "Player"){
	
		playerHealth.health -= 75;
	}
		
	if(c.gameObject.tag == "Untagged"){
	yield WaitForSeconds(3);
	Instantiate(e, transform.position, transform.rotation);
	Destroy(gameObject);
	}
	
}

And also sometimes its effects the enemy and when it does its effects only one enemy (the enemy’s is very close to each other.
I am sure the enemy is tagged as Enemy and the player as Player
Can someone help me? thank you.

2

I think i fixed it, now i need the bomb to kill all of the enemy’s that close to the enemy See:
| = enemy
_ = bomb

this is how its look
| _ |

And its killing only the first enemy.