Celebs Pay Tribute To Aaron Carter Following His Death

Aaron Carter's death came as a shock not only to his family, but to the entertainment world ... and many celebs are now paying tribute to the late pop star.

Actress Hilary Duff took to Instagram to express her sadness over AC's death ... "For Aaron– I'm deeply sorry that life was so hard for you and that you had to struggle in front of the whole world. You had a charm that was absolutely effervescent…boy did my teenage self love you deeply. Sending love to your family at this time. Rest easy."

Reality star Paris Hilton weighed in on Twitter ... "Sad to hear about the news of @aaroncarter 😢 He was always kind to my family and I. He had a good heart. Gone way too soon. 😔Sending my thoughts and condolences to his loved ones and family.  RIP 🙏"

Grammy Award-winning songwriter Diane Warren gave some words of wisdom ... "fame at a young age is often more a curse than a blessing and Surviving it is not easy. RIP Aaron Carter🎤💔."

Singer Tyler Hilton -- no relation to Paris -- shared fond memories of Aaron ... "No….This news is heartbreaking… this kid had such a spark. Known him for years and always really liked him, he was warm and really funny. Loved putting on a show and he was good at it. Ill find some pics of us and post more later… damn RIP budddd #aaroncarter."

TMZ broke the story ... Aaron passed away Saturday ... police responded to his Lancaster home after receiving a 911 call at 11 AM Saturday that a male had drowned in the tub.

As of now, authorities have not released an official cause of death, but we're told police will be doing a deep dive into his past drug use.