Answer:
whose lives were at risk if they stayed behind.
Step-by-step explanation:
By 1974, it became certain that the Republic of Vietnam would fall. Thousand of southern Vietnamese were escaping by sea and air. The Northern Vietnamese troops were at the border of the southern capital of Saigon by April 1975. The President of the United States gave order for the evacuation of U.S civilians and the Vietnamese who were at risk. Around seven thousand people were evacuated by airlifts in the final phase of evacuation called Operation Frequent wind.