During the fall of Saigon, one Vietnamese family in a helicopter, low on fuel, gets rescued by a US Navy ship, the USS Kirk. The Kirk goes on to rescue 20,000-30,000 (estimated) refugees. All of this was forgotten until recently.
I can't imagine being so desperate that I would drop my children out of a flying helicopter.
http://www.npr.org/templates/story/story.php?storyId=129554870