Lisa Glenner wrote, "My father and his family lived at Ptasia 4. The
street has since been destroyed. How do I found out where it was and
who owned the building before WW2?"

In addition to the moderator's recommendation to check the databases
at http://www.jewishgen.org/databases/Poland/WarszawaHomeowners.htm,
you might also wish to look at the 1930 homeowners list in "Ksiega
Adresowa 'Cala Warszawa,'" which is otherwise mostly an address and
business directory (I had forgotten it even included a homeowners list
until recently reminded by the Jewish Historical Institute). To view
this directory, you will need to install (once) a .DjVu plugin for
your web browser. I use the free one available from
http://www.caminova.net/en/downloads/download.aspx?id=1. Then, go to
the first page of the homeowners section, at
http://genealogyindexer.org/frame/d219/212/d, and turn the page
forward until you reach your street of interest, which should appear
in alphabetical order. Ul. Ptasia appears at
http://genealogyindexer.org/frame/d219/292/d, and the owner of number
4 is listed as "Suk. Blassa Jankla." So, someone >from the Blass
family owned the building in 1930. In the 1939/1940 telephone
directory, an Icek Majer Blass is listed at that address. On
geni.com, there is an entry for an Icek Meir Blass, son of Jankel,
which could fit:
http://www.geni.com/people/Icek-Meir-Blass/6000000011253859185.

The 1930 directory images above come >from the Mazovian Digital
Library, where you can even download the entire directory:
http://mbc.cyfrowemazowsze.pl/dlibra/docmetadata?id=813.

For additional information about residents and businesses at that
address (such as entries >from the 1939/1940 telephone directory), try
searching for it, enclosed in double quotes ("ptasia 4"), at
genealogyindexer.org.

Logan Kleinwaks
kleinwaks@...
near Washington, D.C.