User blog comment:Sara J Newgate/new orphan/@comment-25942629-20160925115932/@comment-25942629-20160929125311

It is also entirely possible that they lived with their biological parents until the virus struck. We don't have any information about their parents or living situations before that. Yu was only separated from his parents shortly before the Apocalypse. If his mom didn't try to burn him alive, he could have been with his parents until they died from the virus.