Visits to top-tier indoor shopping malls across the United States were down by 6.5 percent in September amid rising COVID-19 cases and kids returning to school, according to the September mall index from analytics firm Placer.ai. The mall index focuses on 100 top-tier malls and 100 outdoor centers across the United States. July saw shoppers returning to malls in their droves, with visits to indoor malls rising 1.0 percent above the same month in 2019, in part due to a lack of travel and general excitement about the retail industry reopening after months of lockdowns. But things began to quiet down in August, when those numbers dipped to 2.5 percent. And the declines continued on into September, when visits to outdoor malls were also down 5.2 percent. However, experts are still optimistic about the future, noting that this summer’s “artificial” influx of shoppers was down to a “unique mix of factors” and was inevitably set …