Actress and singer Whitney Houston has died in Los Angeles at the age of 48.
Friends and celebrities have been sharing their reactions online and to the media. Here is a selection of their comments.
Aretha Franklin, singer and Houston's godmother
I just can't talk about it now... It's so stunning and unbelievable. I couldn't believe what I was reading coming across the TV screen.
Clive Davis, record industry executive and long-time mentor
(Speaking at his pre-Grammy Awards party) Whitney was a beautiful person and a talent beyond compare. She graced this stage with her regal presence and gave so many memorable performances here over the years. Simply put, Whitney would have wanted the music to go on and her family asked that we carry on.
Mariah Carey, singer
Heartbroken and in tears over the shocking death of my friend, the incomparable Ms Whitney Houston. She will never be forgotten as one of the greatest voices to ever grace the earth.
Bobby Brown, singer and former husband
(On stage in Southaven, Missouri) First of all, I want to tell you that I love you all. Second, I would like to say, I love you Whitney. The hardest thing for me to do is to come on this stage.
Dolly Parton, singer
Mine is only one of the millions of hearts broken over the death of Whitney Houston. I will always be grateful and in awe of the wonderful performance she did on my song [I Will Always Love You], and I can truly say from the bottom of my heart, "Whitney, I will always love you. You will be missed.
Lionel Ritchie, singer
She was just a gift in voice. She was just so innocent in the business, and that voice was so pure and her life was so pure. That's what I'm holding on to. I think what we're going to do in the long run of her life story is focus on the voice. Not the tragedy, but the voice.
Quincy Jones, music producer
I am absolutely heartbroken at the news of Whitney's passing... I always regretted not having had the opportunity to work with her. She was a true original and a talent beyond compare. I will miss her terribly.
Simon Cowell, producer
She was a legend. These people don't come around often. No one could sell a song like Whitney... And to hear this news, it's really, really upset me.
Christina Aguilera, singer
We have lost another legend. Love and prayers to Whitney's family. She will be missed.
Gloria Estefan, singer
Whitney was always so sweet to me! Was rooting for her through her struggles! Such a shame...I'm truly saddened by this news!
Barry Manilow, singer
I can't believe that Whitney is gone. My heart goes out to her family, to Clive (Davis), and to everyone who knew and loved this amazingly talented and beautiful artist. I will always love her.
Smokey Robinson, singer and producer
I've know Whitney since she was a little girl and I loved her. She was like family to me. I will miss her.
Ricky Martin, singer
RIP Whitney Houston. Sending my love and deepest condolences to her family and friends.
Rev Al Sharpton, civil rights activist
The morning of the Grammys, the world should pause and pray for the memory of a gifted songbird.
Tony Bennett, singer
It's a tragedy. Whitney Houston was the greatest singer I've ever heard and she will be truly missed.
Spike Lee, film director
God Bless The Dead. Whitney Houston R.I.P. She Was Only 48 Years Young.
Rihanna, pop star
(On Twitter) No words, just tears
Neil Portnow, head of the Recording Academy, which runs the Grammy Awards
A light has been dimmed in our music community today, and we extend our deepest condolences to her family, friends, fans and all who have been touched by her beautiful voice.