According to her manager, Chyna was found dead in her bed at her Redondo Beach home on Wednesday.
Redondo Beach police said a friend went to check on Chyna at her apartment in the 900 block of Esplanade after she hadn't answered her phone in days. Police initially reported the death as a "possible overdose," Los Angeles County's Assistant Chief Coroner Ed Winter said.
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Investigators said the Los Angeles County Coroner's Department would determine the exact cause of death, but stated there were no indications of foul play.
Chyna rocketed to fame as a wrestler in the World Wrestling Federation from 1997 to 2001.
She began lifting in her hometown of Rochester, New York, at the age of 15, and at one time could reportedly bench press 325 pounds.
Chyna was open about growing up in a home with alcoholism and would later have her own documented struggle with drugs.
In 2007, viewers saw a different side of Chyna when she appeared on the reality TV show "The Surreal Life." She also appeared on "Celebrity Rehab with Dr. Drew" the following year.
Chyna later pursued a career in porn, stating her first adult film gave her a newfound confidence to get back on her feet.
She also posed in "Playboy" magazine and had a New York Times' best-selling autobiography titled "If They Only Knew."
Chyna's manager said she was on prescription medication for sleep deprivation and severe anxiety, but stated he was not sure if that played a role in her death.
Many media reports listed her age as 45, but her manager told ABC7 that she actually turned 46 in December. Redondo Beach police and the coroner's department also identified her as 46 years old.
"She was truly a pioneer in our industry, and she will be missed," tweeted Stephanie McMahon, an owner and executive with WWE.
Laurer was "someone who wasn't afraid to blaze her own trail and create a path for those who would follow," wrestler Triple H said on Twitter. "A pioneer whose star shined bright. #RIPChyna."
Laurer billed herself as the "9th Wonder of the World" because her wrestling predecessor Andre the Giant had already called himself the eighth. She was a member of the wrestling squad that dubbed itself "D-Generation X," was often pitted against men and at one point was the WWE women's champion.
A statement posted Wednesday night on her website reads, "Today we lost a true icon, a real life superhero. Joanie Laurer aka Chyna, the 9th Wonder of the World has passed away. She will live forever in the memories of her millions of fans and all of us that loved her."
She joins a long list of WWE professional wrestlers who have died relatively young, including Rick Rude, Curt "Mr. Perfect" Hennig, the Ultimate Warrior and Owen Hart.
The Associated Press contributed to this report.