An effort by Arizona Republican Gov. Doug Ducey to use shipping containers to close a 1,000-foot gap in the U.S.-Mexico border wall suffered a brief setback when two stacked containers somehow toppled over. A correspondent for the digital platform of Univision Noticias posted on her Twitter feed a photo she took Monday of the containers on their side near the western border community of Yuma. No witnesses came forward to say what happened Sunday night. Contractors told the correspondent they thought monsoon winds toppled the containers. A Ducey spokesman doubted that and suggested someone opposed to the wall was responsible.