I think they buried it into the sea so the that his grave will not beome a pilgrimage site.
I doubt that his death will make a huge difference either way. He hasn't been directing stuff since a while now and as to retaliation...don't know, I think Al-Quaida etc will always have a reason anyway to attack iyswim.
I've lived in NYC for years and was there on 9/11, 5 months pregnant. News this morning brought that day and the ones that followed back in a such a detail 
I'm glad the fucking bastard is dead.