Anna Nicole Smith, a former Playboy playmate who became tabloid fodder when she married an elderly billionaire, collapsed in a South Florida hotel room today and died in a local hospital, police said. She was 39.

The cause of her death is under investigation, Police Chief Charlie Tiger of Seminole, Fla., told reporters this afternoon.

He said Smith's private nurse called the hotel operator at 1:38 p.m. to report that Smith had collapsed. Her bodyguard administered CPR to her several minutes later, and she was rushed to Hollywood Memorial Regional Hospital in Hollywood, Fla., Tiger said. Hospital officials informed police at 2:49 p.m. that Smith was dead, the police chief said.

He said the cause of death will be determined by the Broward County medical examiner and that police from the local crime lab are processing the scene as a precautionary measure. There was no indication yet that any crime was committed, Tiger said, adding, "We're just taking all precautions at this time."

Smith checked into the Seminole Hard Rock Hotel and Casino on Monday and was staying with Howard K. Stern, her lawyer and companion. Stern was not present when she collapsed, Tiger said, and his whereabouts were not immediately known.

Tiger said it was not clear why Smith had a private nurse with her or precisely what she was doing in South Florida. He said she had previously stayed at the hotel and that he presumed she had come there again "to relax."

Edwina Johnson, chief investigator for the Broward County Medical Examiner's Office, said an autopsy would be performed on Smith's body Friday, the Associated Press reported.

Her attorney, Ron Rale, told the news agency that he had talked to Smith on Tuesday or Wednesday and that she had flu symptoms and a fever and was still grieving over her death of her son last year.

"Poor Anna Nicole," Rale said, according to AP. "She's been the underdog. She's been besieged . . . and nobody should have to endure what she's endured."

In a statement, Hugh Hefner, the founder of Playboy magazine, said he was "very saddened" to learn of Smith's death. "She was a dear friend who meant a great deal to the Playboy family and to me personally," he said.

Smith, born Vickie Lynn Hogan in Houston in November 1967, parlayed her resemblance to Marilyn Monroe and her bubbly personality into a tumultuous career as a topless dancer, model, actress, reality TV star, weight-loss product spokeswoman and all-purpose "celebrity."

Catapulted to fame on the March 1992 cover of Playboy and by her selection as the 1993 Playmate of the Year, the buxom blonde married oil tycoon J. Howard Marshall II in 1994 when she was 26 and he was 89. She had met him three years earlier when she was performing in a Houston strip club.

After Marshall's death 14 months after their marriage, Smith became embroiled in a lengthy legal dispute with his son, E. Pierce Marshall, over her late husband's estate, valued at $1.6 billion. She was awarded $474 million by a federal court in California, a ruling that was subsequently overturned. The case ultimately wound up in the Supreme Court last year, but E. Pierce Marshall died a month later at age 67.

Tragedy struck Smith in September last year when her 20-year-old son by her first marriage, Daniel Smith, died in his mother's hospital room in the Bahamas. Smith had just given birth to a daughter, whose paternity is in dispute. Her son's death was ruled the accidental result of a combination of drugs, including methadone and two antidepressants.

After appearing in Playboy, Smith began an acting career and had roles in several movies in the 1990s. Her performances were generally panned, but her protracted legal battle over her late husband's estate, her ballooning weight and episodes of bizarre behavior kept her in the pages of supermarket tabloids.

In 2002, she appeared in her own reality TV series, "The Anna Nicole Show" on the E! Entertainment Television cable channel. The show, which featured Smith, her entourage and her miniature poodle and focused on her struggles with her weight and her precarious financial situation, lasted until 2004, when it was canceled.

Then came a strange appearance in November 2004 at the American Music Awards, where a slimmed-down Smith slurred her speech introducing a musical act and referred to the weight-loss product TrimSpa, which was employing her as a spokeswoman. Although she had reportedly lost nearly 70 pounds and had regained her voluptuous figure, the episode fueled speculation that she was on drugs, which her representatives denied.

Smith announced in June 2006 that she was pregnant, and she gave birth to a daughter, Dannielynn Hope Marshall Stern, in September in the Bahamas. She said the father was Stern, her longtime attorney, but a former boyfriend, photographer Larry Birkhead, asserted that he had fathered the girl, and he filed a lawsuit to press his claim.

Smith's son Daniel died three days after the birth while visiting his mother and his newborn sister at Doctors Hospital in Nassau. Later that month, Smith and Stern exchanged vows aboard a catamaran off the coast of the Bahamas. Although a Baptist minister was reportedly present, no formal marriage certificate was issued, and another lawyer for Smith told reporters that the union was not legally binding.