However, go the link given below for a thorough look at German air-raid measures. See advertisements for gas tight doors & doors with peep holes that appeared in German publications.
such as:


See Pressac thoroughly debunked on this and his other absurd 'criminal traces' here:
http://codoh.com/library/document/883
PLUS, see how the bogus US 'holocau$t' Museum claims a bomb shelter door is a 'gas chamber' door here:
http://www.vho.org/GB/c/DT/gcturen.html
- Hannover