US Marines worked to reinforce the southern border wall near Tijuana on Monday, January 27, as defense officials said approximately 1,600 army and marine personnel had been deployed to support border protection.Footage from the US Marines, released by DVIDS, shows marines with the 1st Combat Engineer Battalion working to fortify the southern border wall near the San Ysidro border crossing in San Diego.The US Northern Command said the marines are “working hard to protect the territorial integrity of the United States along with US Customs and Border Protection.” Credit: US Marines/DVIDS via Storyful