‘THERE’S NOTHING FESTIVE ABOUT BOARDED-UP STOREFRONTS:’ Union Square retailers look different this holiday season.

As San Francisco approached the critical December shopping month, instead of holiday lights and Santa Claus decorations, dozens of downtown retailers greeted shoppers with plywood-encased storefronts and armed guards in the wake of mass retail thefts in Union Square two weeks ago.

Around a half-dozen stores in the Union Square area were boarded up on Tuesday, including the Louis Vuitton store and others that sustained damage during the robberies. Other luxury stores such as Gucci, which Mayor London Breed said had an existing security gate system and wasn’t damaged in previous robberies, had a guard outside as well.

It’s a stark contrast from previous years when December in Union Square was marked by windows full of holiday ornamentation and the seasonal enticement of products that could fit under Christmas trees.

San Francisco morphed into Detroit so slowly, I hardly even noticed.