Leo and Piper do not die in the Hereos of Olympus.
She died because after her and Piper got attacked by the demon, Leo only had time to save one sister, and he saved Piper, so it was too late to save Prue as Leo can't heal the dead. Hope I helped
Yes My Favorite Show A New Destiny Without Piper I Don't like Piper Married Leo Don't like I Want Prue Married Leo Prue Need To Stay Save Phoebe And Pagie New Charmed Ones Prue,Phoebe And Pagie Stay Away Demon Please Stay Alive Yes let Prue Go Out First Date With Leo
Prue died by Shaks, The Source's assassin. He through Prue and Piper through a wall Leo was in the underworld with Phoebe and when he got back he healed Piper first and it was too late to heal Prue.
The episode is the season 3 final and is called All hell breaks loose
Carl Piper died in 1716.
William Piper died in 1852.
Jesse Piper died in 1920.
Leonora Piper died in 1950.
Christina Piper died in 1752.
Edward Piper died in 1990.
Charles Piper died in 1926.
Piper Davis died in 1997.