Police said the man, identified as 34-year-old Jdimytai Damour, was a temporary employee who lived in New York City's borough of Queens.
In addition, police officials said a pregnant woman was taken to a local hospital, but was expected to be released Friday.
Video footage showed as many as a dozen people knocked to the floor in the stampede of people trying to get into the Wal-Mart store, according to Nassau County Police detective Lt. Michael Fleming. The employee was "stepped on by hundreds of people" as other workers attempted to fight their way through the crowd, Fleming said.
"We expected a large crowd this morning and added additional internal security, additional third party security, additional store associates and we worked closely with the Nassau County Police," said Hank Mullany, Wal-Mart's vice president for the Northeast, in a statement. "Despite all of our precautions, this unfortunate event occurred."
"Our thoughts and prayers go out to the families of those impacted," he added, saying the company is cooperating with authorities in their investigation. (Full story)
Around the nation, shoppers descended upon Wal-Mart (WMT, Fortune 500) en masse in hopes of scoring Black Friday discounts. From New Jersey to Dallas, there were reports of hundreds of shoppers lining up before stores opened, looking for $2 DVDs and flat-panel TVs priced just under $400.
At the Fairfax, Va., location, the scene was social. Hundreds queued up before doors opened at 5 a.m., with some having arrived the night before in order to be among the first to shop.
"We skipped Thanksgiving dinner," said 30-year-old Arash Habiezadeh.
Wal-Mart, which operates more than 4,100 U.S. stores and 3,100 international locations, is expected to be a big winner this holiday season as its discounts resonate with budget-conscious shoppers. The company has been aggressively courting customers by lowering its prices and introducing holiday-gift sections in stores.
"Even with the economy, you've got to go with the deals," said Robert Balboni of Centreville, Va., while loading his shopping cart with a 42-inch flat panel TV, a portable DVD player and a Philips 2GB MP3 player.
Wal-Mart has already shown signs of benefiting from the economic slowdown. Same-store sales, or sales at retail stores open at least a year, gained 2.4% in October, beating the company's own forecast.
Overall, the U.S. retail sector is expected to endure one of its worst holiday seasons in years. Sales are projected to climb just 2.2%, according to the National Retail Federation, making it the weakest sales gain in six years.
-- The Associated Press, CNN's Christina Cinnici and CNNMoney.com senior writer Parija B. Kavilanz contributed to this story.
Retail sales suffer another huge blow
Wal-Mart’s profits rise as it draws from rivals
Retailers’ holiday deals begin early
Holiday job picture not so jolly
