Destroy only when hit from the top

I want to destroy an object when it is hit from the top only i.e. I have a man in a multistory building that is made from one type of object. When he walks on or into this object nothing must happen but when it falls on him he must die. The building material has physics property.

You could pin a hitbox to his head and check for collision with the hitbox.

Thanks, that will work :-)

If that doesn't work, or you want to have a collision for the entire object for other purposes, you can add another object to that one and pin it to the object, that way the hitboxes will be separate