This is an amazing story, looking for old chicago images, real estate agent John Maloof  bought a box of old negatives at a chigago antique auction.
When he started to scan the negatives he discovered that he had instead stumbled upon the trove of perhaps one of the greatest street photographers of the mid-20th century. Maloof discovered that this wealth of work came from Vivian Maier, a nanny who worked in Chicago from the 1960s into the '90s.
It took quite some time till he found her name on one of the envelopes and when he googled her he only found her 3 days old obituary.

http://vivianmaier.blogspot.com/