Bottom line here i think is that there's no right or wrong answer here. there's no rule to follow. if you feel the need to express condolence in flowers or similar, and that helps you deal with the situation, regardless of your connection, go for it. Not everyone will feel that way, and there's nothing wrong with that - if it doesn't make you want to drop flowers, it just hasn't struck your particular nerve in the same way.
Everyone is different, everyone is unique in how they handle things, so drop flowers, mourn the loss of the childhood icon that was a favourite family pasttime. Remain stoic and aloof - again, there is no right or wrong response to this incident - with the possible exception of throwing a party \ celebration \ cheering that people died.