MINNEAPOLIS— The family of a man who was among six people gunned down at his Minneapolis office last year are suing the company, claiming it botched the firing of the employee who carried out the attack and should have known he was mentally ill and potentially dangerous.

The lawsuit being filed on behalf of Jacob Beneke’s family is the first to come from Andrew Engeldinger’s Sept. 27 attack on Accent Signage Systems, said the family’s attorney, Phil Villaume.  

The Associated Press obtained a copy of the lawsuit in advance of Friday’s formal announcement.

“It’s probably one of the most horrendous, saddest cases I’ve ever been involved in in my 33 years of lawyering,” Villaume said. “The Beneke family has suffered terribly, beyond comprehension. It’s just a very, very sad situation all the way around.”

Engeldinger, 36, fatally shot Beneke, four other co-workers and a UPS deliveryman before taking his own life.

The company had repeatedly cited Engeldinger for offensive behavior, tardiness and poor job performance, and it warned him a week before the attack that executives wanted to meet with him about his employment on the day of the attack. That day, Engeldinger was reminded of late afternoon meeting, and before heading in, he when to his vehicle to retrieve a gun. When company executives told him they were firing him, he pulled it out and began killing.

Engeldinger’s parents have said he was mentally ill but had refused their offers to get him help. His mother declined to comment for this story.

The wrongful death suit, which names the company and Engeldinger’s estate as defendants, alleges that Accent Signage should have known from Engeldinger’s pattern of behavior that he had violent tendencies, suffered from a severe mental illness, and could hurt or even kill others.

The lawsuit says the company acted in a careless, negligent and grossly negligent manner when it gave Engeldinger notice of his potential firing in advance and allowed him to go to his vehicle. The lawsuit claims the company had no security cameras that would have filmed Engeldinger as he retrieved his weapon, and there was no extra security on hand for his meeting.

The lawsuit says: “a reasonable employer in Accent’s position would have, among other things, provided adequate security on its premises, locked its doors, monitored Engeldinger, and would have attempted to terminate Engeldinger in a safe manner.”

“They should’ve had security. They didn’t take action. They knew they had a problem employee,” Villaume said. “We have reason to believe that he was planning this for a long period of time. He was going through gun training at a gun range and had become quite proficient, if you will, at handling a handgun.”

According to the lawsuit, Engeldinger was hired in 1999 and worked in Accent’s engraving department. Beneke was hired in 2005 as an engraver, and eventually became a supervisor in the digital imaging department.

The lawsuit says Engeldinger held personal animosity toward Beneke, and Beneke often called Engeldinger his “nemesis.” The company’s owner and founder, who was also killed in the attack, told Beneke on Sept. 24 that Engeldinger was going to be fired three days later and that the information should be kept secret.

The lawsuit alleges that Beneke knew Engeldinger was prone to violence, and that he was afraid of what might happen on the day of the shooting. Beneke drove a different vehicle to work and told his wife, “It’s good I’ll have the truck, because if he (Engeldinger) goes crazy, he won’t recognize that I have a different car,” the family contends.

The lawsuit claims Accent is liable for Engeldinger’s wrongful acts. Villaume said the Beneke family is seeking “substantial” damages. Beneke, 34, left behind a wife and a young son.

Messages left with Accent Signage and with the attorney handling Engeldinger’s estate were not immediately returned Friday.

Villaume said the lawsuit is important, especially given the recent attacks like the one in Newtown, Conn., in which 20 elementary school students were gunned down.

“It’s about time that people step up and speak out against gun rights,” he said. “Guns in the hands of dangerous people are a dangerous thing, and they kill and harm and maim innocent people — and that’s what happened here.”

The shooting at Accent Signage was Minnesota’s deadliest workplace shooting.