Chicago police are investigating the theft of lug nuts from squad cars sitting in a police station parking lot on the city’s Southwest Side. The lug nuts began disappearing about a week ago. No officers have been involved in road accidents because of the apparent vandalism, officials said. “It’s not funny,” a Morgan Park District officer said. “You could lose control and run into a building or a person or another car.” No suspects have been identified, but officers also discovered a concrete slab in the Morgan Park District police parking lot painted with an anarchy symbol.