Julie Couvillon, 36, was walking down Bourbon Street with friends in the early hours of Sunday morning, when she was fatally struck by a bullet

An innocent female bystander was fatally shot in New Orleans on Sunday after a man stole security guard's gun and opened fire outside a bustling restaurant.

Louis Barnes, 37, was reportedly being ejected from the popular eatery Willie's Chicken Shack in the city's French Quarter for allegedly attempting to sell drugs on the premises.

Eyewitnesses reported that Barnes, aggrieved by the situation, became entangled in a scuffle with the restaurant's security guard outside, grabbed his gun and fired off several rounds.

Barnes reportedly shot the guard, himself, and a bystander - Julie Couvillon, 36 - who was walking down the street at the time of the altercation.

The mother-of-one had been enjoying a 'rare' night-out with friends on Bourbon Street when the gunfire erupted in the early hours of the morning.

Louis Barnes, 37, was arrested on Sunday and now faces life behind bars. Police say he shot himself, the guard and Couvillon in the altercation

Julie became a registered nurse in 2005. A spokesperson from the medical center where she worked described her as a 'beloved' and 'dedicated' worker

A nurse, Couvillon was hit by a stray bullet and rushed to hospital where she was later pronounced dead.

'It doesn't make any sense,' her friend Rosaleen Brown to the New Orleans Advocate. 'It just breaks my heart that her daughter doesn't have a mom anymore.'

Police haven't yet publicly identified Couvillon as the victim, but her death has been confirmed by friends on social media.

It's not yet clear where she was struck by the bullet.

Couvillon has been a registered nurse since 2005, and had worked for the past 13 years at Ochsner Health System.

'Julie was a beloved nurse who dedicated her life to caring for others,' a spokesperson from the medical center said in a statement on Sunday.

'This is a devastating loss to the nurses, employees, physicians and staff across our system. We offer our deepest condolences to her family and the families of the other victims.'

Barnes was jailed on Sunday evening and faces charges of second-degree murder and attempted murder.

The mother-of-one (pictured left with a friend) was pronounced dead shortly after arriving in hospital

A stampede of panic reportedly occurred as the gunfire rang out. One man was injured in the chaos

Workers at Willie's Chicken shack (pictured) say the defendant was asked to leave the premises after he was allegedly caught trying to sell drugs

Workers at Willie's Chicken shack say the defendant was asked to leave the premises after he was allegedly caught trying to sell drugs.

Authorities say he then grabbed the security guard's gun and discharged the weapon several times, shooting himself in the shoulder, the security guard in the neck, and killing Couvillon.

The guard, working on behalf of Elite Protection Solutions (EPS), had only been the job for just over a month.

His condition is described as stable and EPS owner, Willie Harris, says he has movement in all of his body, except his left arm.

A fourth man was said to have been hurt in the stampede of panic that followed the gunfire, but didn't suffer serious injuries.

New Orleans Police Chief Shaun Ferguson said 'This will not be accepted,' during a pres conference.

Barnes faces life imprisonment if convicted of Couvillon's murder.

The 36-year-old has a long-history of run-ins with the police, online court records show.

The guard's condition is described as stable and EPS owner, Willie Harris, says he has movement in all of his body, except his left arm

Last month, Barnes appeared in court after he failed to register as a sex offender while out on a $5,000 bail bond. He was due back in court on Monday.

He previously pleaded guilty to have sex with a 14-year-old girl in 2011, and received a two year sentence.

In 1997 he was arrested for attempted burglary and two years later he was found guilty of the battery of a school teacher, aged 17.

More charges of burglary, drugs possession, firearm possession and skipping out on bail have all followed since.

He was sentenced to five years in prison in 2012, having pleaded guilty to the firearm charge.

'We take extra measures in hiring our own security detail to make sure our patrons and staff are safe at all times,' Willie's Chicken Shack said in a statement on Sunday.

'This tragedy during the Mardi Gras season should serve as a message that our community needs to be as diligent as ever to combat crime in the French Quarter.'