The Earth Quake

None knows me, the structure i am. They just estimate about what i am! Iam really a walking man, miles and miles, and always where i pass, i leave every thing cry. I have a special force, to break some hills, i have great force, to break the rocks. None in the world, can block my way, i pass where i need though it's night. Really i am a man, a man from men to shake the world as heavy as it is!