The thread topic makes me think of either a retirement community or a, "safe house" for crooks, not a sandbox environment for novice superheroes. How can the two be combined?
Until recently, the city was home to a retired criminal mentalist. He would use his abilities to subtly influence the criminals on the lam, "Don't plan your next job until you leave." Everything stayed quiet, and nobody had any reason to investigate. Now he's dead, and his influence has worn off. We've got a large group of crooks who are getting bored, thinking about trying something.