// instantiates graphic explosion, destroys bomb, decrement health
void Explode()
{
GameObject explosion = Resources.Load("GraphicExplosion") as GameObject;
Instantiate(explosion, transform.position, Quaternion.Euler(0, 0, 0));
Destroy(this.gameObject);
bg.FreeRegion(region); // tell bomb generator that region is now free
gm.DecreaseHealth();
}
