my $location_hash = get_location(\*ZIPS);
my $cat_hash = get_categories (\*SICS);

for my $city ( keys %$location_hash ) {
   printf "%s %s %s\n", $city, $location_hash->{ $city }->{ 'ST' }, $location_hash->{ $city }->{ 'ZIP' } ;

   for my $cat ( keys %$cat_hash) {
      printf "%s %s\n", $cat, $cat_hash->{ $cat }->{ 'NUM' } ;
      .
      .
      .

      delete ($location_hash->{ $city }) ;            ###  This is what I want.... Does not work
      delete ($location_hash->{ $city }->{ 'ZIP' } ); ###  Does not work
      delete ($cat_hash->{ $cat }->{ 'NUM' });        ###  Does not work
      delete ($cat_hash->{ $cat });                   ###  This is what I want.... Does not work

   } # for my $cat ( keys %$cat_hash)
} # for my $city ( keys %$location_hash ) {