A post-mortem examination is to be carried out on the body of pop superstar Prince as the world comes to terms with his sudden death.
The American musician, hailed by Sir Elton John as the "greatest performer I have ever seen", was found collapsed in a lift at his home in Minneapolis on Thursday.
Medical staff tried to revive the 57-year-old but he was pronounced dead at the scene, said Carver County Sheriff Jim Olson.
Listen to a recording of the 911 call below.
A cause of death was not immediately given but showbusiness website TMZ reported that he had been treated for a drugs overdose days before his death.
The singer was taken ill on April 15 while flying home from a show in Atlanta, Georgia.
His private jet made an emergency landing in Molina, Illinois, and the Purple Rain star was taken to a nearby hospital by ambulance, where he was treated and released hours later.
At the time, a representative for Prince assured fans that he was feeling much better and was resting at his Paisley Park home.
And just five days ago the singer made an appearance at a dance party held at his estate where he told fans: "Just wait a few days before saying your prayers."
But less than a week later paramedics were called to 7801 Audobon Road after a 911 call at 9.43am. Medics tried CPR but could not revive Prince, who was pronounced dead at 10.07am local time.
Fans quickly gathered outside his home and tributes flooded in for the music maverick, including a touching message from US President Barack Obama, ahead of his arrival in the United Kingdom.
Mr Obama said the world had lost a "creative icon".
Madonna, who collaborated with Prince on Love Song on her album Like A Prayer, posted a picture of the two of them together on Instagram, writing: "He Changed The World!! A True Visionary. What a loss. I'm Devastated."
Film director Spike Lee wrote on Instagram: "I Miss My Brother. Prince Was A Funny Cat. Great Sense Of Humor" and later invited fans to pay tribute to the singer at a street party in New York.
Elton John shared a picture of Prince on his Instagram page, writing: "This is truly devastating news.
The greatest performer I have ever seen. A true genius. Musically way ahead of any of us. Sang with him twice on stage. What an honour. Rest in peace you purple warrior. #Prince #RIP"
Scottish singer Sheena Easton, who cast aside her squeaky clean image to feature on his song U Got The Look, said: "It is impossible to imagine him not being here. The world of music was forever changed the day he picked up his guitar. His talent was breathtaking, his heart was kind, and all of us have been blessed to have had a glimpse into this sweet and magical soul."
Prince became an international superstar in 1982 after his breakthrough album 1999 and was most famous for hits including Purple Rain, When Doves Cry and Kiss.
His won seven Grammy Awards, sold more than 100 million records and won an Oscar for Best Original Song Score for Purple Rain.
The singer, who was just 5ft 2in, was also seen as an eccentric with a tendency towards bizarre career moves, such as changing his name to an unpronounceable symbol in the 1990s.
He became even more famous with the release of the film Purple Rain in 1984, a seemingly autobiographical movie set in the club scene in his home town of Minneapolis.
He was fiercely protective of his independence, battling his record company over control of his material and even his name.
Prince was married twice, the first time to his backing dancer Mayte Garcia, from whom he split in 2000, and then Manuela Testolini, whom he divorced in 2006.
He was in the process of writing an untitled autobiography which was due to be published in 2017.
Sales of Prince's music soared after news broke of the pop star's death, and shortly after his death was announced fans gathered outside his home to pay tribute.
His sister, Tyka Nelson, came out of the house and told fans that her brother "loved all of you. Thank you for loving him back".
She looked at the bouquets, balloons and signs left by fans before approaching the crowd of nearly 200 to speak.
The owners of the central Minneapolis nightclub where Purple Rain was filmed planned an all-night dance party in his honour.
First Avenue owner Dayna Frank said the club wanted to give people a place to share their emotions and celebrate Prince's life.
The Carver County Sheriff's Office released the transcript of the 911 call from Prince's Paisley Park compound which sent emergency workers to the home.
An unidentified man struggles to find the address to give to the call handler, at first saying only that he is "at Prince's house" and a person is unconscious.
He later says the person is dead and continues: "And the people are just distraught."
When the call handler asks if he knows how the person died, he says: "I don't know, I don't know."
After confirming the address, the dispatcher begins to ask a question and the caller interrupts to say: "Yes, it's Prince."
At the end of the call, another ambulance dispatcher comes on the line to cancel any other paramedics on their way to the address as the person is "confirmed DOA" (dead on arrival).