An autopsy on the body of Amy Winehouse revealed no cause of death Monday for the 27-year-old retro-soul singer, leaving fans and family to wait for the results of toxicology tests due in two to four weeks.

A funeral for Winehouse, who was Jewish, was likely to be held Tuesday or Wednesday.

"I can't tell you what this means to us," father Mitch Winehouse told fans gathered Monday outside her home in London's Camden district. "We're devastated and I'm speechless, but thanks for coming."

The singer's mother, Janis, was in tears as she examined the flowers, candles, vodka bottles, flags, drawings and handwritten cards left by neighbors, fans and well-wishers. Many of the offerings expressed the same sentiment: "What a waste."

Winehouse, who'd last spoken to members of her team around 10 a.m. Saturday, may have been dead for several hours before she was found by security guard Andrew Morris in her home that afternoon.

"She was in her bedroom after saying she wanted to sleep and when [Morris] went to wake her he found she wasn't breathing," Chris Goodman, her rep in Britain, told the Sun. "He called the emergency services straight away. He was very shocked.

"At this stage no one knows how she died. She died alone in bed."

The frail singer had been getting regular doctor checkups, the Sun said, most recently the night before her death. Her family said Monday that reports their daughter had bought cocaine, ketamine and ecstasy hours before she died were "nonsense."

Though only in her 20s, Winehouse reportedly suffered from emphysema as a result of smoking cigarettes and crack cocaine. Winehouse's last public appearance came Wednesday when she briefly joined her goddaughter, singer Dionne Bromfield, on stage at the iTunes Festival near Camden. Winehouse didn't sing, but danced and clapped and encouraged the audience to buy Bromfield's album.An inquest into the singer's death was opened and adjourned at London's St. Pancras Coroner's Court on Monday. During the two-minute hearing, an official read out the name, birthdate and address of Winehouse, described as "a divorced lady living at Camden Square NW1."

Ex-husband Blake Fielder-Civil, currently serving a 32-month jail sentence for burglary and gun possession, was "in total shock" and inconsolable upon hearing about the death, girlfriend Sarah Aspin told the Sun. Winehouse had most recently been on-and-off dating Reg Traviss, 33, a film director described as a "normal bloke."

The scene at Winehouse's home had been investigated and "determined non-suspicious." In Britain, inquests are held to establish facts when a person dies violently or in unexplained circumstances. Winehouse's inquest will resume Oct. 26.