Residents complained about missing packages, mail delivery late at night, or not at all.
"We had been advocating with the postal service over the last year about staffing needs, about improper training of the carriers," said Mack Julion, president, National Association of Letter Carriers Local #11.
Organizers say postal officials told them staff quitting or becoming injured on the job is part of the problem, primarily in the 60622 zip code.
