Benyamin Robinson, 28, forced his way past security at the home delivery terminal of the FedEx warehouse in the 5100-block of West 73rd Street in the southwest suburb around 8 a.m. Armed with a revolver, witnesses say Robinson, last known to live in Chicago, yelled for his wife and then fired several shots.
Oneal Howell said he doesn't know what led his son to violence.
"What he did was out of frustration. I don't know what was bothering him," Howell, gunman's father, said. "Some people are open about it. And others keep it in. When you keep it in and it bubbles over, anything can happen."
Investigators said Howell's wife, Kenyata Kinsey, filed for divorce, but then retracted. Initial calls at 8 a.m. were for a domestic situation, but they escalated.
"At 8:04 a.m. we started getting calls from FedEx employees that shots were fired," the Bedford Park Police Chief Daniel Godfrey said.
"It was just chaotic. People running, nobody really knew. It was just surreal," Michael Georgeff, FedEx driver, said.
"I did not see the guy, because he had on a gray hoodie, but he was running -- maybe a mile behind us -- and shooting in the air when we got outside," Altis Kelly, FedEx package handler, said.
"We were just running outside, I heard multiple shots, about three, four shots. That's when me and him just ran out of there," Jeff Luna, FedEx driver, said.
"From what we understand, it was people stuck in the building with the shooter. We were just praying they're alright. But we did hear somebody got shot. We don't know who," John Colapietro, FedEx driver, said.
During those tense moments, the plant was evacuated and searched by SWAT team members from Bedford Park and seven or eight nearby agencies. Once the gunman was surrounded, Robinson shot himself in the head, police said.
"They discovered the shooter inside a vehicle with self-inflicted gunshot," Chief Godfrey said. "The only injured was the shooter."
The Bedford Park police chief said the shooter's children were located safe. He said there was no indication of prior domestics and the couple's last known address was in Chicago.
All of the FedEx employees were accounted for by 9:45 a.m., when sources told ABC the "incident is over."