Catherine O'Hara's cause of death has been released, one week after the Canadian comedic actor died at the age of 71. The Schitt's Creek star died on Jan. 30 from a pulmonary embolism, with rectal cancer listed as an underlying cause, according to O'Hara's death certificate, which was obtained by Rolling Stone and People on Monday afternoon.According to the death certificate released by the Los Angeles County Medical Examiner's Office and viewed by Global News - first secured by TMZ - O'Hara died at a Santa Monica, Calif., hospital and her body was cremated.