Stars took to Twitter to voice their sadness at the death of British soul singer Amy Winehouse, with many calling her demise a tragic waste of her talent.
Friends, fellow entertainers and well-known public figures expressed their shock on the micro-blogging website after the 27-year-old was found dead at her north London home.
Others simply paid tribute to the troubled vocalist, whose drink and drug problems were often acutely clear.
Mark Ronson, who produced many of Winehouse's hit singles, said in a statement: "She was my musical soulmate and like a sister to me. This is one of the saddest days of my life."
Fellow producer Salaam Remi, who also worked on Winehouse's albums, wrote on Twitter: "Very, very sad day. Just lost a great friend and a sister. RIP my baby sis Cherry Winehouse. Love ya always."
Rolling Stones guitarist Ronnie Wood dedicated his radio show, and Saturday's live performance by his previous band The Faces, to the late singer.
"It's a very sad loss of a very good friend I spent many great times with," he said.
US actress Demi Moore tweeted: "Truly sad news about Amy Winehouse. My heart goes out to her family. May her troubled soul find peace."
British singer Lily Allen said: "It's just beyond sad, there's nothing else to say. She was such a lost soul, may she rest in peace."
Chef Jamie Oliver wrote: "Such a terrible shame to lose Amy Winehouse. Such a talent, such a waste, raw talent."
Sarah Brown, the wife of former British prime minister Gordon Brown, said: "Just heard the sad news that Amy Winehouse has died.
"At only 27 what a terrible waste of a great talent. Sincere condolences to her family."
CNN television presenter Piers Morgan called it "desperately sad news".
"Supreme talent, terrible self-destructive addictive personality,'' the former British tabloid newspaper editor wrote.
US country singer LeAnn Rimes wrote: "RIP Amy Winehouse. So sad to see such a talent gone and her life end in tragedy. This makes me terribly sad."
Singer and actress Kelly Osbourne said: "I can't even breathe right now I'm crying so hard. I just lost one of my best friends. I love you forever Amy and will never forget the real you!"
The troubled singer, whose struggle with drink and drugs overshadowed her sultry musical talents, had been found dead at her flat in north London, emergency services said.
The Grammy award-winning soul singer with her trademark beehive battled with well-documented addictions that she documented in her hit single "Rehab".
Her death is being treated as unexplained, police said.
"We were called at 3:54 pm (0254 NZT) to an address in Camden Square," a London Ambulance Service (LAS) spokeswoman told AFP.
"We sent two ambulance crews, a cycle responder and a duty manager to the scene. Sadly the patient had died. Both ambulances had arrived within five minutes."
A section of the road outside Winehouse's home has been cordoned off and police officers are on duty at the scene where reporters, local residents and fans had begun gathering.
Forensic officers were seen going in and out of the building.
A police statement said: "Police were called by LAS to an address in Camden Square shortly before 4:05 pm (0305 NZT) today, Saturday 23 July, following reports of a woman found deceased.
"On arrival officers found the body of a 27-year-old female who was pronounced dead at the scene.
"Enquiries continue into the circumstances of the death. At this early stage it is being treated as unexplained."
There was no immediate comment from her agents.
The singer had a European comeback tour schedule but pulled out following a disastrous opening performance in Serbia on June 18.
In the run-up to her live return, Winehouse spent a week at an addiction treatment clinic in London, reportedly at the suggestion of her father, Mitch, over concerns that she was drinking too much.
But she was booed at the opening performance in Belgrade, apparently too drunk to sing.
Some 20,000 people gathered for the highly-promoted concert at the sixth-century Kalemegdan fortress, but many soon left.
During the 90-minute concert, Winehouse could only mumble some of the lyrics, failing to follow her band.
She left the stage twice, with many fans showing their displeasure despite her band's attempts to calm the crowd.
"Amy Winehouse is withdrawing from all scheduled performances," a statement from her representatives said.
"Everyone involved wishes to do everything they can to help her return to her best and she will be given as long as it takes for this to happen."
She had also been scheduled to perform in Istanbul, Athens, Bilbao in Spain, Locarno in Switzerland, Italy's Lucca festival, Switzerland's Paleo Festival in Nyon, Nova Jazz and Blues Night in Wiesen, Austria, and Poland's Bydgoszcz Artpop Festival.
She made her final public appearance at The Roundhouse venue in Camden on Wednesday, joining her goddaughter Dionne Bromfield on stage.
She danced with Bromfield and ecouraged the audience to buy the youngster's album before leaving.