Is Loop in Chicago a safe neighborhood?

Yes, the Loop is safe. As one of the main areas that people visit when they come to town the police force is extra concerned with making sure no one gets into any trouble, and there's so much business here that if crime were a problem it would be a huge issue.

Unless the Joker is in town, as it was on Lasalle Street that he had a confrontation with Batman. That might make it a bit less safe.