A disgruntled former employee at an Orlando, Florida RV accessory business fatally shot five workers Monday morning before turning the gun on himself, according to the Orange County Sheriff’s Office.

The shooting was first reported around 8 a.m. at the headquarters for Fiamma, Inc. Once deputies arrived on scene, they found three men and one woman already dead, Orange County Sheriff Jerry Demings said during a press conference.

A fifth man was transported to a nearby hospital where he died, according to Demings.

Authorities believe suspect John Robert Neumann Jr., 45, who was fired in April, shot himself just before deputies entered the scene two minutes after they were first called, Demings said at a later press conference.

Demings said it appeared Neumann had a "negative relationship" with at least one of the victims, but "was certainly singling out the individuals that he shot."

One eyewitness, a young woman who was a temporary worker at the business, told authorities that the suspect pointed his gun at her and told her to "get out" of the business, he said.

The victims were identified Monday afternoon as Robert Snyder, 69; Brenda Montanez-Crespo, 44; Kevin Clark, 53; Jeffrey Roberts, 57; and Kevin Lawson, 46.

Neumann was a U.S. Army veteran who was honorably discharged in 1999, Demings said. He lived alone and had no family in the area, he said.

This March 19, 2010 booking photo made available by the Seminole County Sheriff's Office, shows John Robert Neumann Jr., who was arrested for possession of marijuana. AP File

The shooter arrived at his former place of work with a semi-automatic handgun, a large hunting knife, and possibly a couple of other, smaller knives, police said. There were approximately 12 people in the building at the time of the shooting, according to police, eight of whom were witnesses to the attack.

Most of the victims were shot in the head, Demings said, and some were shot multiple times.

Demings said that the former employee had a minor criminal history, including DUI, marijuana possession and misdemeanor battery.

However, he added, police had been called to Fiamma Inc. before because the suspect had been involved in a "workplace violence" incident. Neumann was not arrested over the incident, which took place in June 2014, Demings said.

Demings said there was no indication the suspect was involved in any kind of terror plot.

A sister of one of the employees told reporters gathered at the scene that her relative was using the bathroom when she heard a "loud bang."

Shelley Adams, of South Orlando, said her sister, Shelia McIntyre, told her that when she exited the bathroom, she saw a deceased victim on the ground.

Adams said her sister and others were taken to a nearby fire academy, but Adams didn’t know how many people were with her sister and if they were also employees of the business.

Authorities confer, June 5, 2017, near Orlando, Florida. John Raoux / AP

Florida Governor Rick Scott issued a statement, asking Floridians to pray for those impacted by the shooting.

"Over the past year, the Orlando community has been challenged like never before," Scott said. "I have been briefed by our law enforcement officials on this tragic incident and Ann and I are praying for the families who lost loved ones today."

The shooting comes just one week before the first anniversary of the Pulse nightclub shooting in Orlando, in which 49 people were killed, one of the worst mass shootings in U.S. history.

Orange County Mayor Teresa Jacobs asked that the public be vigilant, and report any activity that seems suspicious.

"The situation here appears to be very different than the situation at Pulse," Jacobs said. "They appear to be two separate incidents. I would ask citizens that if you see behavior that troubles you … make the call."