In the ThunderClan, the dogs killed the leader - Bluestar. Bluestar shows the traits we often think of when dying a heroic death: she died after risking her own life to save the rest of the clan from the dogs. The dogs basically maul her to death, which is a gruesome way to go. Luckily for readers, the death is not described in detail, as this is a children’s book.
This comes from a book called “A Dangerous Path”, which is actually the fifth book in the series. The series is titled “Warriors”. It came out on June 1st, 2004 in the United States. It was later published around the world, in places like the UK and China, and released as a hardback, paperback, and an e-book.