TAMPA — The Sam's Club warehouse that served South Tampa for 18 years is closing along with dozens of others across the country as parent company Walmart pivots to focus on e-commerce.

A sign taped to a window at the 5135 S Dale Mabry Highway location said Thursday it was closed and would reopen Friday. However, the closure appears permanent: A phone recording tells pharmacy customers its last day will be Jan. 26; the company website has dropped the store from its online list of Tampa Bay area locations; and Business Insider listed it among 63 affected stores.

"After a thorough review of our existing portfolio, we've decided to close a series of clubs and better align our locations with our strategy," Sam's Club posted on Twitter Thursday afternoon. "Closing clubs is never easy and we're committed to working with impacted members and associates through this transition."

Up to 12 of the 63 stores will be converted to e-commerce distribution sites to speed delivery of online orders, the company said in statement. The first will be in Memphis, Tenn. It's unclear whether the Tampa store is among the 12.

A Walmart official told the Associated Press that at least eight stores closed Thursday and the rest would shut down in the coming weeks.

The Sam's Club closures, affecting thousands of workers, coincided with Walmart's announcement that it would boost its starting salary for U.S. workers to $11 an hour and hand out one-time cash bonuses. The displaced employees will get their bonuses, along with 60 days of pay, and for those eligible, severance, the company said.

"We know this is difficult news for our associates and we are working to place as many of them as possible at nearby locations," said John Furner, president and CEO of Sam's Club. "Our focus today has been on those associates and their communities, and communicating with them."

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Sam's Club still has stores in North Hillsborough County, Wesley Chapel, Brandon, New Port Richey, Clearwater, Pinellas Park and St. Petersburg.

The pharmacy recording at the South Tampa location said prescription records will be sent 17 miles away to the Brandon Sam's Club on 2021 West Brandon Blvd.

The closure of the South Tampa location stunned customers who arrived Thursday expecting to find roast chicken and office supplies but instead got a note on a door and unsettling rumors.

"This is a bad move," declared Sofia Pohlmeyer of South Tampa, 65, who visited with her husband in the afternoon. They shop weekly at the store, she said, typically stocking up on meat, paper products, cleaning supplies and water, sometimes dropping in to pick up dinner. She lamented the fact that, because of distance, a Sam's Club in North Tampa won't offer the same spontaneous convenience.

"This community needs this kind of store with bulk purchases," she said.

Cathleen Grillo, 76, of Harrison, Mich., spends part of the year in an RV park at nearby MacDill Air Force Base. She drove into the Sam's Club parking lot with her husband to pick up a few things, only to learn the news. It puzzled her to learn that the store closed unexpectedly Thursday but planned to reopen for a couple of weeks.

"That's a strange way to do business," she said.

Felix Santana, 59, had another reason for concern. A payment was due on his Sam's Club credit card Thursday and the shutdown thwarted his attempt to pay. He had no idea the store was closing.

"It means, I guess, we're going to have to go to Costco," he said.

Earlier this week, South Tampa subscribers of the community bulletin board Nextdoor were hashing out the virtues of Sam's Club vs. Costco, with fans on both sides, but some told of routinely making the drive to the Brandon Costco over the Lee Roy Selmon Expressway. On a good day, it's 20 to 25 minutes.

Then, Thursday, they noted the demise of Sam's Club, closer to home.

Media outlets in states including New York and North Carolina reported Sam's Club closings there, too.

The wave of closures is likely a reaction to the highly competitive and oversaturated retail landscape in the United States, said Steven Kirn, executive director of the University of Florida's retail education and research center.

"The consensus in the real estate and financial markets is that we are over stored. We have more stores in the United States than we need," Kirn said. "My sense is that Sam's Club has never gotten the traction that Costco has in terms of customer loyalty and average basket size."

Walmart could have handled the store closings better, he said.

"My impression is that they weren't ready to announce the store closures today," he said. "It either leaked or rumors were spreading. It seems like employees were not informed. This is a lot of people, maybe a couple of hundred employees per store."

Many customers took to social media to complain to the retailer and demanded a refund on their membership. The company provided a link where they could get a full refund.

Twitter users in Alaska questioned the wisdom of closing all the stores in the northernmost state.

"Closing @SamsClub in #Fairbanks or even #Alaska in general, is the dumbest thing I've heard," a user named Chandi Napier, "Where are people gonna buy bulk items during the winter at a decent price?? Especially with everything being so expensive here? #Costco wouldn't do this to us."

Contact Jonathan Capriel at 813-225-3141 or jcapriel@tampabay.com. Follow @jonathancapriel.