The evacuation continued until the morning of 30 April with the last helicopter evacuating the Marine Security Guards from the roof of the U.S. Embassy at 07:53 and landing on USS "Okinawa" at 08:30. At 11:30 North Vietnamese tanks smashed through the gates of the Presidential Palace less than 1 km from the Embassy and raised the flag of the Viet Cong over the building, ending the Vietnam War.