Catherine O'Hara's cause of death has been revealed.
O'Hara, 71, died from a pulmonary embolism, with rectal cancer as the underlying cause, according to a death certificate obtained by Fox News Digital. The certificate also shows O'Hara was cremated.
The Los Angeles Fire Department previously confirmed to Fox News Digital that first responders were dispatched to O'Hara's Brentwood home at approximately 5 a.m. on Jan. 30. She was transported to a local hospital, where she was listed in serious condition. The beloved actress was pronounced dead several hours later.
"Prolific multi-award-winning actress, writer, and comedian Catherine O'Hara died today at her home in Los Angeles following a brief illness," her reps confirmed to Fox News Digital.
CATHERINE O'HARA DISCOVERED RARE MEDICAL CONDITION DURING ROUTINE DOCTOR VISIT WITH HUSBAND OVER 20 YEARS AGO
Over 20 years before her death, O'Hara had discovered she had dextrocardia situs inversus - a rare medical condition during a routine doctor visit.
"He calls us into his office and says, 'You're the first one I've met!'" O'Hara recalled during an episode of "Virtual Happy Hour" with Kathryn Hall in 2020. "I don't even know the name, because I don't want to know the name. Something cardio-inversus. And then dextrocardia and something-inversus."
"People are going to think I'm so ignorant not to know this, but I kind of don't want to know. Because I didn't know before that."
O'Hara's career spanned decades, defining moments in Hollywood comedy - from her scene-stealing performance as the exasperated yet endearing mother in the blockbuster "Home Alone" films to her unforgettable turn as the eccentric Moira Rose in "Schitt's Creek."
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O'Hara's film career includes an extensive list of leading and supporting roles in some of Hollywood's most beloved movies, including "Beetlejuice" and "The Nightmare Before Christmas," among many others.
Later in her career, O'Hara achieved some of her greatest acclaim for her portrayal of Moira Rose.
For the final two seasons of "Schitt's Creek," she received an Emmy Award, a Golden Globe, a SAG Award, a Critics' Choice Award, a TCA Award and multiple Canadian Screen Awards.
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Her recent TV performances in "The Last of Us" and "The Studio" earned her Emmy nominations for outstanding guest actress in a drama series and outstanding supporting actress in a comedy series.
O'Hara is survived by her husband, production designer Bo Welch, and their sons, Matthew and Luke, along with her siblings Michael O'Hara, Mary Margaret O'Hara, Maureen Jolley, Marcus O'Hara, Tom O'Hara and Patricia Wallice.
Fox News Digital's Stephanie Giang-Paunon and Christina Dugan Ramirez contributed to this report.
