Oh, boy.
@puffluna
this is not ideal.
The nest needs to be inside a covered fence or shelter to be safe.
You are right - the ducklings could get trampled to death by morning. Bring them in, keep them warm enough (I would use a thermometer to be sure). Set out a little water - if they have just hatched, they won't need food overnight, but will some time tomorrow.
An old towel will be fine for bedding for tonight, and a box in a room where they won't be touched by anyone or anything overnight (when I was younger, a young cousin let the dog into my room, and it killed my ducklings, so I know anything can happen if you are not really careful).
If the mom and the rest of the ducks can be in a safe shelter, I'd consider actually nabbing the rest of the eggs and keeping them warm overnight, also. Yes, I would. Glad you thought to ask about this. You are in a rough spot, and doing your best.