AHC holiday scene, 1983
Construction workers put up a tree in a precarious place during the construction of the on campus hospital, circa 1983. The photograph is part of the University Hospitals Board of Governors records at the University Archives.
Addendum
Thanks to several comments (see below), a more accurate description of the image is that of "topping out" the frame of the hospital. Although the photograph was taken between November and January, the tree is much more likely a representation of a long time tradition in building construction.
Update
The photograph was taken on December 13, 1983.

Comments
A reader emailed me with the following information regarding the photograph of the tree on top of the building.
Thank you Emilie for this information!
Erik
Posted by: Erik Moore | January 2, 2007 09:43 AM
This tradition is called "topping out." When the steel structure of a building is complete, the workers traditionally place a tree there (regardless of whether it is near Christmas-time or not, though if it does happen to be in the holiday season, they will sometimes decorate it like a Christmas tree). Therefore, you wouldn't be able to assume that this photo was taken around the holidays based purely on the fact the tree is there.
You can still see sometimes find trees on buildings under construction even today, though apparently these days it is getting more popular to place a flag there instead of a tree.
Posted by: ldfs | January 2, 2007 10:10 AM