The New York Daily News reported that witnesses said shoppers continued to stream past emergency crews as they worked furiously to save the 34-year-old worker's life, before the Valley Stream, N.Y., store was closed.
A statement by Nassau County Police said the incident occurred shortly after the store's 5 a.m. opening time, when shoppers "physically broke down the doors, knocking [the worker] to the ground."
As many as six other people, including a pregnant woman, also suffered minor injuries in the incident, according to reports.
"We're saddened to report that a gentleman who was working for a temporary agency on our behalf died following the incident and a few of our customers were injured," a Wal-Mart spokeswoman said, reading from a statement. "Our thoughts and prayers are with them and their families at this difficult time. At this point, facts are still being assembled, and we're working closely with Nassau County Police as they investigate what occurred.
"The safety and security of our employees is our top priority," the spokeswoman said. She declined to comment further because the investigation is ongoing.