We "rescued" four after Mama poked her head up under the mower.
Fed 'em kitten formula. Three died within two days. The fourth was quickly joined by a week old male kitten. They spent the first month of their lives together until the rabbit died of unknown causes. The cat lived a good long life.
Long story short, even if you do try to save them, you might not be able to save them. Do what your conscience leads you to do, but realize that they may still not make it.