How did Cinderpelt save Sorreltail's life?

When Sorreltail began to have her kits, badgers began to attack the ThunderClan camp. Cinderpelt defended them as well as she could, but it was useless. Cinderpelt was severely wounded, and Leafpool, (who had ran away from the forest with WindClan cat, Crowfeather), walks in just as Cinderpelt was about to die. After she had died, Sorreltail named one of her kits, (a grey she-cat), Cinderkit, after Cinderpelt, who gave her life to save Sorreltail and her kits.
-With help from warriors.wikia.com.