I am using a script to instantiate multiple objects having rigidbody with different velocities at different positions. I want to destroy two or more objects when they collide, but I'm not getting anything inside:

    void OnCollisionEnter(Collision collision){}


The details of the object I'm instantiating. https://i.sstatic.net/dKhgm.png

The script is attached to an empty GameObject and Instantiated GameObject is stored in a array of GameObjects:

     Block[0] = Instantiate(boxPiece) as GameObject;

where boxPiece is the Object I want to instantiate.
And I'm checking for collisions in this very same script.