the beginning....

I was thinking that the best way to start the story is with a 'big bang' where a major event occurs which I think will be effective in capturing the audiences' attention, perfect example is the opening of New Hope with the star cruiser battle. So going back to gangsters context probably a bank heist which again is similar to Dark Knight, or a bar fight but it could also be a small big bang in that it doesn't have to be something with explosions it could be that someone owes money to the mobsters and has to pay it back or they exact their threats on him. Just a thought that could get the ball rolling.