Whom can I be angry at?

Anger is a natural part of grief, but I did not feel it until a few days after Avi's death, when I learned from Menachem about Chris Porreca and Avi's activities on Digital Pandemic.

Menachem had logged onto Avi's MSN Messenger account and found Chris (userid "kaok") trying to contact Avi. Menachem informed him of the news and Chris immediately revealed his full identity and gave his phone number. Menachem called and found Chris in tears. Menachem could literally hear him trembling. Until then, Chris had no idea how young Avi was.

When Menachem related his conversation to me, I became at once proud and angry - proud over Avi's brilliance, accomplishments and advanced coding knowlege, and angry over Avi's loss of his promising future, but I did not know whom to get angry at. I did not blame God (although that would have been okay), because God did not strike him. I did not blame his doctors, nurses and other caregivers at the hospital, because I knew that they had done all that was humanly possible. I did not get angry with Avi (anger at the deceased is normal and not unusual), because he had done nothing to contribute to his demise.

So, whom can I angry be at - the virus that triggered the events? Avi's auto-immune response? Bad genes? Unthinking, insensate strands of protein with DNA or RNA?

I guess I'm angry because I need to be angry - anger hides feelings of intense grief - but I have no one to be angry at!