It all began Friday when Justine Sacco tweeted, "Going to Africa. Hope I don't get AIDS. Just kidding. I'm white!"
By the time she landed, the tweet had gone global and she'd been fired by Internet giant InterActive Corp., which owns Match.com, Dictionary.com, Vimeo and other popular sites.
In a statement to ABC News, Sacco apologized on Sunday.
"Words cannot express how sorry I am, and how necessary it is for me to apologize to the people of South Africa, who I have offended due to a needless and careless tweet," Sacco said. "There is an AIDS crisis taking place in this country, that we read about in America, but do not live with or face on a continuous basis. Unfortunately, it is terribly easy to be cavalier about an epidemic that one has never witnessed firsthand."
The offending tweet and Sacco's Twitter account have been deleted.
ABC News contributed to this report.