Why is Finny's death important in A Separate Peace?

Finny's death is the final break in the rift between Gene
and Finny that developed as Gene struggled to deal with feelings of envy and jealousy
toward his friend.  Finny had always been the center of attention, and Gene, always
aware of that, inadvertently recreates the familiar scene when he pushes Finny out of
the tree.  Normally, Gene would run to help, but this time he did not, but rather stood
by watching as others rushed to Finny's aid.  Ironically, Finny's accident not only
breaks the friendship of the two boys once and for all, but it breaks the spell Finny
held over Gene as Gene is forced to see Finny as just another kid, a mere mortal, who is
injured (Gene is particularly moved by the sight of Finny being carries away on a
stretcher, like any other human being who was seriously injured, and not the god-like
figure Gene had created in his mind).  Gene also sees Finny when he (Finny) is emotional
and afraid, and thereafter, Finny dies during an operation to repair his injuries.  The
death of Finny, in some ways, occurs figuratively even before it does literally; even
before Finny dies, Gene behaves as if he's already gone, visiting all the places the two
had frequented during their time together.  It is fortunate that Finny and Gene make
their peace before Finny dies, because it is only after he is gone that Gene realizes a)
how much Finny meant to him, and b) what a good and appreciative friend Finny had been.