AURORA, Illinois—A laid-off employee killed five people at his place of work in Aurora, Illinois on Friday, according to authorities.

Officials said Gary Martin, 45, fatally shot five people and wounded six more, including five responding police officers at the 29,000-square foot warehouse of the Henry Pratt Company at around 1:30 p.m. Martin is dead, Aurora Police Chief Kristen Ziman said. Two officers were immediately shot when they arrived at the water valve company. Because families were still being contacted Friday evening, the department said it was "unable to release any names of identifying information at this time."

Martin worked at the company for 15 years and was terminated on Friday, according to ABC Chicago. Law-enforcement officials told ABC that Martin produced a gun during his termination meeting.

Employee John Probst told ABC Chicago he saw Martin carrying a pistol and heard several gunshots before running out the back of the building.

“One of the guys was up in the office, he said this person was shooting, and, he come running down and he was bleeding pretty bad, and the next thing you know he was walking back and forth, I heard more shots, and we just left the building,” Probst said.

Martin’s mother told the Chicago Sun-Times that her son was recently “way too stressed out.”

Martin had a violent past: he was convicted in 1995 of aggravated felony assault in Mississippi, according to public records. Law enforcement was seen searching his home in Aurora following the shooting, but officials say they have no reason to believe anyone else was involved.

Ziman addressed the wounded officers at a press conference, thanking them “for your selfless act.”

“It’s a shame that mass shootings such as this have become commonplace in our country,” Aurora Mayor Richard Irvin said. “It’s a shame that a cold and heartless offender would be so selfish as to think he has the right to take an innocent life.”

At around 7:30 p.m. the Kane County Sheriff’s department and other law enforcement officials were still at Martin's apartment in the Acorn Woods Condominium complex in the northeast part of Aurora, roughly five miles from the Henry Pratt Co. office.

In the parking lot, neighbor Jeremy Sherman and his girlfriend, who declined to be identified, watched the scene. Sherman’s girlfriend confirmed Martin had been a resident of the complex for 10 years; Sherman moved in last July and described having occasional interactions with Martin. The rears of their apartments faced each other, and Sherman said Martin could often be found outside playing with his remote control cars and drones.

He described his neighbor as something of a loner; he says the two smoked weed together a few times and chatted, but never learned anything about the 45-year-old, including anything about his work life or his past. Sherman said he never saw Miller with weapons — or guests for that matter, and would come home even at odd hours to find Martin outside.

"He kept to himself a lot and he was always on his porch. Even when he wasn’t doing nothing, he’d be out there sitting,” Sherman said. "I’d be to there, sometimes one, two [o’clock] in the morning and he’d be there just sitting all in the dark, [in the] shadows.”

Sherman added, "I’d say something to him sometimes and he’d be like 'rorh rorh rorh,' mumbling under his breath. I don’t know if he heard me or…I don’t know. He seemed a little off the wall, a little off his rocker, you know? Not like mentally crazy, but something about him was just a little bit different.”

Sherman said everyone in Aurora knows about the Henry Pratt Company because it’s a “huge” employer in the area, but that he learned of Friday’s shooting when his mother alerted him that his neighbor was the suspect.

As details continued to trickle in about Martin, Sherman was still processing that a mass shooting happened so close to him. "You see this kind of stuff on the news a lot, but for it to hit your neighbor?”

In a final update for the day late Friday evening, Chief Ziman confirmed that Martin was a 15-year veteran of Henry Pratt who was being terminated. It’s unclear as to whether any of the victims were in the termination meeting. “We don’t know if he had the gun on him during the meeting, or if he went to retrieve it,” Ziman said of the roughly hour and a half-long incident.

As police investigate Martin’s background, Ziman said police weren’t aware of any prior contacts with the police, or if he had been previously known to local law enforcement.

Asked if the department was "treating this as a classic workplace shooting, or are you still looking at whether or not [Martin] was targeting people there for other reasons?” Ziman passed and shook her head: “I hate that we have to use the term ‘classic workplace shooting.’ That pains me to do so. At this time, I don’t know.”

Ziman said police are still trying to learn more about Martin’s “mindset” and if the shooting was premeditated in any way.

Family members of employees at the plant told The Daily Beast they were told by the company not to speak to the press.

Workplace homicides account for about 10 percent of all fatal occupational injuries in America, according to the Bureau of Labor Statistics. In 2016, the most-recent year of available data, 66 people were killed by coworkers.