A worker died after being trampled by a throng of unruly shoppers when a suburban Wal-Mart opened for the holiday sales rush Friday, authorities said.

At least three other people were injured.

Wal-Mart Stores Inc., in Bentonville, Ark., would not confirm the reports of a stampede but said a "medical emergency" had caused the company to close the store, which is in Valley Stream on Long Island.

Nassau County police said the 34-year-old worker was taken to a hospital where he was pronounced dead at about 6 a.m., an hour after the store opened. The cause of death was not immediately known.

A police statement said shortly after 5 a.m., a throng of shoppers "physically broke down the doors, knocking (the worker) to the ground." Police also said a 28-year-old pregnant woman was taken to a hospital for observation and three other shoppers suffered minor injuries and were also taken to hospitals.

The exact cause of death will be determined by the Medical Examiner’s office, detectives said.

The dead worker's name was not released.

"Local authorities are looking into the situation," said Wal-Mart representative Dan Fogleman. But he said it would be "inappropriate for me to share any additional information" until authorities investigate further.

The two people shot and killed inside a crowded Toys "R" Us store in Palm Desert on Black Friday were identified as two Hispanic men, Sgt. Dennis Gutierrez of the Riverside County Sheriff's Department said.

"We got a call of shots fired," sheriff's Sgt. Dennis Gutierrez said. "We went in the store and we have two dead individuals."

There was no immediate word of any relationship between the victims or what caused the shooting to erupt. Deputies say they were not looking for any suspects. No one else was injured in the incident.

Two handguns were recovered near the bodies early Friday evening as Central Homicide investigators combed the store after the shooting.

The names of the victims have not yet been released.

The incident happened just before 11:30 a.m. at the store located at 72314 Highway 111 near Fred Waring Drive.

An eyewitness said she saw two men shoot each other as shoppers and their children jammed the store seeking "Black Friday" bargains.

The Desert Hot Springs woman, who gave her name only as Joan, said she was about 6 feet away from the shooting when it occurred.

"The blonde lady came over and started pummeling the other, Hispanic lady," Joan told City News Service.

"That's when the guy took out the weapon," she said.

According to the witness, the man accompanying the blonde was the first to pull a gun, and then the man with the other woman pulled out a gun as well.

Joan said she quickly ran, then ducked down to avoid getting hurt.

"It wasn't my time to die," Joan said.

Several Palm Desert city officials were told by police on what exactly happened.

According to Palm Desert city councilman Jim Ferguson, two men with handguns shot and killed each other.

Ferguson says he asked police whether the incident was a dispute over a toy or whether it was gang-related. He says police told him they are not going to release further details until the victims' relatives are notified.

City spokeswoman Sheila Gilligan says police told her the shooting broke out in the Toys 'R' Us between two groups of individuals who have a dispute with each other.

Several people were detained following the shooting. News Channel 3 cameras captured at least two people outside the store being detained including a woman who was heard screaming and banging on a Sheriff's cruiser.

Sgt. Gutierrez said the women detained were people with information on the shooting and were not officially arrested or charged with anything.

Deputies told News Channel 3 that some shoppers inside were evacuated while others were kept in the store shortly after the shooting as deputies swept the store for suspects.

Toys"R" Us issued a statement expressing its outrage "by the act of violence" and "the fact that anyone would compromise the safety and security of our customers and employees."

"We are working closely with local law enforcement officials to determine the specific details of what occurred," the statement said. "Our understanding is that this act seems to have been the result of a personal dispute between the individuals involved. Therefore, it would be inaccurate to associate the events of today with Black Friday."

Daniel Watson's wife and mother-in-law were inside the store at the time of the shooting. Watson told News Channel 3 that he was on the phone with her wife as shooting rang out. Watson's wife called back to tell her husband that she was safe and her mother escaped the store.

Some Toys "R" Us shoppers who fled the store sought refuge in a gym across the street.

"All of a sudden a dozen to 15 people came in distressed," Jeff Vallaire, who manages the World Gym on Town Center Way in Palm Desert, told City News Service. "One of them had an infant who was crying.

"They said there was a shooting, they heard five or six shots and they fled out the back of the store," Vallaire said.

Vallaire said several law enforcement officers came into the gym and spent roughly an hour interviewing shoppers who had been in the Toys "R" Us store at the time of the shooting.

The area remained crowded with shoppers and a parking lot across the street, which was sealed off in connection with the shooting investigation remained full, Vallaire said.

Riverside County Sheriff's Department as well as officers from the Cathedral City and Indio police departments are on scene.

The shooting comes on the morning of Black Friday, one of the year's busiest shopping days.

City News Service and the Associated Press contributed to this report.