Whitney Houston's final days

Whitney Houston's death is not considered suspicious, but investigators are still trying to figure out what happened.

"The family is making arrangements," Assistant Chief Coroner Ed Winter said Monday. "I don't know when the family is going to have her body picked up. But they are making arrangements and sometimes it takes a couple days."

An autopsy on the singer was completed Sunday; however the coroner is not officially saying what killed the six-time Grammy winner.

But law enforcement sources tell CBS News the most likely theories for Houston's death (are) that she died of a heart attack or prescription drug overdose, but the exact cause of death won't be known until toxicology reports come out, perhaps (in) as many as six or right weeks.

The sources say there were prescription drugs, but no illegal substances found in Houston's hotel room.

Houston was staying at the Beverly Hilton Hotel for a big pre-Grammy party.

Whitney Houston's family free to collect body

But then, in mid-afternoon Saturday, a 911 call from the hotel brought an ambulance racing to the scene. Paramedics found Houston unresponsive in her hotel room bathtub.

Complete coverage: Pop diva Whitney Houston dead at 48
Special Section: 54th Grammy Awards

The hotel was already busy with fans and photographers looking to see recording stars arriving for one of the big gatherings of the Grammy weekend. Instead, they were there as a van from the coroner's office carried away Houston's body.

Houston had been in a room on the hotel's fourth floor. At 3:43 p.m., someone in her group asked the front desk to call 911. Paramedics arrived quickly, but at 3:55, Houston was declared dead. There was an autopsy Sunday.

"There were no visible signs of trauma," said Ed Winter, assistant chief of the coroner's office, "and foul play is not suspected at this time."

But what killed her remains a mystery.

"There will be no cause of death at this time," Winter said.

Houston's struggles with alcohol and drugs over the years were well-known. But those who saw here in the days just before her death say they saw no signs of trouble.

"We were still waiting for that great comeback," says singer Kenny Lattimer.

He was host of a pre-Grammy party Thursday night when Houston surprised Kelly Price on-stage. "It felt like it was a private moment," says Lattimer, "where she singing, 'Yes, Jesus loves me,' but she was singing it to Kelly, but she wasn't doing it in a way that was particularly for the audience."

Pictures taken of Houston as she left the party suggest she was disheveled, sweating, her hair soaking wet. The photos show spots of blood on her leg.

But Lattimer has only good memories of the last time Houston sang in public. "I felt ... I was looking at a woman who was in good spirits, her natural warm self. ... I just felt like she was happy."

  • John Blackstone

    From his base in San Francisco, CBS News correspondent John Blackstone covers breaking stories throughout the West. That often means he is on the scene of wildfires, earthquakes, floods, hurricanes and rumbling volcanoes. He also reports on the high-tech industry in Silicon Valley and on social and economic trends that frequently begin in the West.