Oh, no... We have now learned Catherine O'Hara's cause of death. Related: Macaulay Culkin Mourns Home Alone Mother's Death Per TMZ's reporting, the legendary actress died at 71 from a pulmonary embolism, with rectal cancer as the underlying cause. More details to come... [Image via MEGA/WENN.] The post Catherine O'Hara's Heartbreaking Cause Of Death Revealed! appeared first on Perez Hilton.