How to animate independent mesh parts I have kind of floor cell made of pieces



I want to animate it so it can fall into pieces.

Do I need to create an armature for it? Or there is a possibility to animate parts of mesh without bones?

I need this animation to be supported by unity.

Update: I think I have an idea how to proceed here. I did a separation into parts as was proposed. But instead adding a physics I can animate these parts manually. Without bones, just save positions of each piece into keyframes. Is it good idea?
Maybe you should try Animation Nodes if you are going for some sort of procedural animation. It gives you the ability to create parametric animations, like ICE in SoftImage or Xpresso in C4D

https://github.com/JacquesLucke/animation_nodes