Sort:  

Who can prove that the library with its content ,burned indeed?

I have made a small research over internet regarding your question.
I have found a source here http://www.hellinon.net/NeesSelides/VivliothikiAlexandreias.htm
In my opinion, it is a reliable source, since I have read a book on the subject and I'm sure it has taken graphic material from the same book I have.
In any case, if you are more interested in the subject, I can look for it.