The `Grey`s Anatomy` star and his actress wife were at home with their 21-month-old daughter Billie Beatrice at the time of the incident but were unhurt when the tree - which is 50 feet long and weighs 800lbs - was knocked over by storms battering Los Angeles.
A nearby resident, Susan Smith told TV station KTLA: "Thank God we`re all okay. We know there are a lot of live wires out there," Smith said. "These winds that came today were unbelievable."
Susan added that the "very pregnant" Rebecca, who is expecting the couple`s second child, was upstairs when incident occurred.
Department of Water and Power officials and firefighters had to attend the scene to turn off power as the tree hit overhead electrical wires when it fell.
The couple - who married in 2004 - have had a traumatic year as Eric checked himself into rehab in June as a "preventative measure" after he feared becoming addicted to painkilling medication prescribed for a sports injury.
His spokesperson confirmed: "Actor EricDane voluntarily checked himself into a treatment facility to help him get off of pain medication that he was prescribed for a sports injury that he suffered over the recent hiatus."