SLAB CITY, Calif. — The dusty compound is cluttered with rusted school buses and wooden shacks. Cacti stud the grounds and Christmas lights drape dried tree stumps. When the wind blows over the nearby Salton Sea, wind chimes serenade as Slab City slumbers. This Shangri-La of desert weirdness has for years drawn tourists from around the world. Some would stay in one of the dilapidated RV’s rented out by Rodney “Spyder” Wild. It cost only $30, and guests got breakfast and running water. But even the “last free place in America,” as locals call it, didn’t stand a chance against COVID-19.