Pacoima, Calif., a largely Latino community on the north end of Los Angeles, is laden with freeways, airports, power plants, chemical manufacturers, and landfills. But residents intent on making their neighborhood a cleaner, safer place to live have teamed up through the nonprofit Pacoima Beautiful. They're working to prevent lead poisoning, clean up trash, repair heavily polluting cars, and turn an asphalt recycling plant into a park. Marlene Grossman and other community activists lead a walking tour of the neighborhood.