Download Fracturing and Destruction FREE Unity. 

The Ultimate Fracturing & Destruction Tool is a Unity editor extension that allows you to fracture, slice and explode meshes into shards.
It also allows to visually edit behaviors for all in-game destruction events like collisions and projectile impacts. This enables to trigger sounds and create dust or explosion particles without any scripting.
Includes four different sample scenes!

Works on Unity 3.5/4.x/5 (No Pro required)