From Wikipedia: '...both the pagan historian Ammianus Marcellinus and the Christian historian Orosius wrote that the Bibliotheca Alexandrina had been destroyed

From Wikipedia: '...both the pagan historian Ammianus Marcellinus and the Christian historian Orosius wrote that the Bibliotheca Alexandrina had been destroyed by Caesar's fire. The anonymous author of the Alexandrian Wars writes that the fires Caesar's soldiers had set to burn the Egyptian navy in the port of Alexandria went as far as burning a store full of papyri located near the port. However, the geographical study of the location of the historical Bibliotheca Alexandrina in the neighborhood of Bruchion suggests that this store cannot have been the Great Library. It is most probable here that these historians confused the two Greek words bibliothekas, which means “set of books”, with bibliotheka, which means library. As a result, they thought that what had been recorded earlier concerning the burning of some books stored near the port constituted the burning of the famous Alexandrian Library.'