[SCRIPT] Get entity speed

[Your Computer]

You don't need a script for one object to break another object. If you remember, entities allow you to specify the force required to be applied to the object in order for them to break. It should be no different than breaking glass or plates with a crate. You should be able to have some kind of collision detection mechanism (e.g. with a sticky area that denies all objects) that checks the health of the object to be broken and if the health is not at a broken level, display the message.