Fell on the ground vs fell to the ground

Last night, I was rushing to catch my train when I slipped over and fell to the ground heavily. I hadn’t seen the wet floor caution they’d put up at the entrance.

Can someone please tell me if the above para sounds natural? Can I use fell on the ground too? Is there any difference between them? Can I use floor in place of ground?

‘Fell to the ground’ is the natural choice. ‘Floors’ are inside buildings. ‘The ground’ is outside.

Thanks a lot, MM.

If I fell upon entering the building, should I say I fell to the floor?

I would.

The verb “fall” suggests a motion with changing of direction such as “fall to the ground”: A person falls from a vertical position to a horizontal position, whereas “on the ground” has to take a stative verb or a dynamic verb able to keep the subject on the plane (without letting it off the plane).