I am guessing that since you're in the US, NC to be exact, that they are most likely cottontails. A cottontail is greyish brown with a white chest and belly, and a white fluffy tail, which gives them their common name.
I've read from this site that says to leave them be (unless they wouldn't otherwise not survive do to injury) and their mother will come to them at nightfall. If the mother rabbit is dead, and you're 100% she is, then and ONLY then should you take in the bunnies, as they are now orphaned.
If their eyes aren't open, you'll have to syringe feed them some formula every couple of hours. I read somewhere that kitten formula (KMR or Kitten Milk Replacer) is what you should be feeding them and to avoid puppy formula at all costs.
Keep in mind that wild bunnies that young rarely survive even with the most expert of care provided. Its best to contact a wildlife sanctuary to take care of them, as they will have more experience and the bunnies will have a better chance at survival.
Here is a site on taking care of orphaned wild bunnies.
Orphaned Baby Bunnies: Wild and Domestic | House Rabbit Society