In an earlier post, I mentioned that I considered rewriting my first chapter to change the initial action from a happenstance into a full-scale ambush. Thinking it over more and more, it makes more sense that it would be an ambush given the nature of the victim (a really powerful hero). The only issue I can see is how to leave future chapters relatively intact while still using the characters in the ambush. The way I see it, the ambush would have to be one of those attackers in silhouette deals, with only a fleeting hint of the abilities each of the attackers possess. The chapter should act as a teaser for the characters future appearances while still giving the idea of the vast network that the principle villain has at his beck and call.
I was just thinking that instead of a lucky hit in the first chapter, maybe it should be an ambush of by characters that I have introduced later in the book, which would bring in the characters earlier and make it more feasible that a random mugger could kill a super hero with a shovel.