LAUDERDALE LAKES, Fla. (WFLA) — An off-duty Florida Walmart worker was arrested on charges of first-degree murder and armed robbery after authorities said he shot and killed a customer who tried to intervene during an altercation with another store employee.

The Broward County Sheriff’s Office said the shooting happened in Lauderdale Lakes Tuesday around 2 p.m. Deputies surrounded the store, located at 3001 N. State Road 7.

There, they say 22-year-old Tironie Sterling, an off-duty employee at the Walmart location, met with a female employee. When an argument between the two escalated into a physical encounter, deputies said a customer stepped in to try to help.

That’s when Sterling and the customer got into a physical altercation, according to the sheriff’s office. During the fight, Sterling shot the customer several times before fleeing the store.

The customer was life-flighted to an area hospital, where he later died.

Hours later, authorities tracked down Sterling and took him into custody. He was sent to the Broward County Main Jail.

Video from inside the Walmart showed worried customers and employees gathered in the parking lot.

A Walmart spokesperson provided the following statement to NBC affiliate WTVJ:

“Senseless violence like this is intolerable, and we’re heartbroken to learn a customer has been critically injured while helping one of our associates. Our thoughts are with him, his family and our associates at this time. The store will remain closed while we continue working with law enforcement.”

Walmart

Shoppers recalled the terrifying moment when shots rang out inside the store. They described taking off running after hearing the gunshots.

“I heard three shots – bam, bam, bam – and they seemed very close so I started toward the front of the store and then one of the employees said ‘no, no, go back, go back, the exit is this way,’ so I went out the back,” a witness told WTVJ.