When his grandfather returned from the war, he learned his mother and sister had both had breakdowns and been institutionalized. They never came home.
If there's a better subreddit for this question please let me know.
Whereabouts in Pennsylvania? If you don't know even the possible region might help (Philly area, Pittsburgh area, Central PA...)
you should try http://www.reddit.com/r/Genealogy/ they are really good at detective work like this