Marina seems like a peaceful place, but in the short time I've been here...there's been several different things that have happened, too. The weather system has gone berserk and injured people, Sentience even reverted us back into how we once were as children. And of course outside of Sentience... there have been other, harmful individuals.
Rido-ojisan...being one of them. But there was also Agatha...and others.
I think while being here we should be prepared for that sort of news. All of these things have happened in about a month's time. Although it is elaborate and fancy for a prison, I wouldn't consider it always...gentle either.