The cause of death for beloved actor and comedian Catherine O’Hara has been officially released, less than two weeks after she died at the age of 71.

According to a death certificate published Monday by the Los Angeles County Medical Examiner’s Office and first reported by TMZ, O’Hara’s immediate cause of death was a pulmonary embolism, a blood clot that traveled to her heart. Rectal cancer was listed as the underlying cause.

O’Hara’s death was initially announced by her manager as the result of a “brief illness.” The death certificate also notes that she was cremated, with her remains released to her husband, production designer Bo Welch.

Over a career spanning five decades, O’Hara became one of the most distinctive and beloved figures in comedy, often playing mothers whose warmth, chaos, and sharp edges felt uncannily real. She was forever etched into pop culture as Kate McCallister, the frantic mom who forgets her son in the first two Home Alone films, giving rise to the enduring “Kevin!” meme. Decades later, she found a new generation of fans as Moira Rose on Schitt’s Creek.

Macaulay Culkin, who played her son in Home Alone, led tributes to his former co-star, writing on Instagram: “Mama. I thought we had time. I wanted more.”

Actor Pedro Pascal, who worked with O’Hara on The Last of Us, also paid tribute, calling her a genius and expressing gratitude for having worked alongside her.

O’Hara earned Emmy nominations late in her career for her work on The Last of Us and The Studio, bringing her total to ten nominations. She won her first Emmy in 1982 for writing while working on SCTV, after joining Toronto’s The Second City in the 1970s.

Born in Toronto on March 4, 1954, O’Hara was the sixth of seven children. Her early years in sketch comedy helped launch a film career that included roles in After Hours and Tim Burton’s Beetlejuice. She later reprised her role as Delia Deetz in the 2024 sequel, Beetlejuice Beetlejuice.

O’Hara met Welch on the set of Beetlejuice. The two married in 1992 and went on to raise two sons, Matthew and Luke.