The explosion should be made completley with the particle system. Then you you script it so the object blows on contact and removes itself from the scene. A great example is on the unity website in the tutorial section. Click on the FPS tut and read it through. There is also a premade explosion in the standard assets in the particles section. Hope this helps!!!

Noone will "send" you a script, this is UnityAnswers, not UnityFreeCommissions. Here's how you can set it up yourself:

• Download the Detonator Pack and extract it into your Unity project.
• Add a small Trigger collider around your mine.
• Create a script using OnTriggerEnter that will instantiate a new instance of a Detonator prefab when the player enters the mine.
• Optionally, destroy the mine game object using Destroy(gameObject);

That will cause a fairly large explosion to take place when someone walks too near a mine.

This is almost like asking around if somebody can write the game for you. That's not so easy. You need to make in example some particles for the explosion. After that a script that when the mine collides with the character, it transforms in the particles object. So at least now you can make that BOOM object with particles now! And later come back and ask how to make a script that transforms an entity into another one when it collides with the character :)