[Matti Salonen]

It is not "Hausern" but "Hans am 21.3." (Hans in 21.3.) as Mike wrote.

My explanation to the text on back side of the photo is:

Fr Setzer
Fw allein
2 x Vergr. 18/24
+ 6.K Zusammen
8/2 45

Possible translation:
For Mrs. Setzer 2 ea prints of size 18/24 cm only from Fw. Additionally 6 kopies of the whole photo. Ordererd (or to be ready) February 2, 1945.

I don't think, that this text has anything to do with the loss itself.

Matti