A gunman who opened fire on his coworkers at a warehouse in Illinois, had been told that day his job was being terminated.
That's according to local authorities, who say 45-year old Gary Martin killed five people before police shot him dead.
Martin is said to have used a revolver and wounded five officers and another sixth coworker, although they are expected to survive.
(SOUNDBITE) (English) KRISTEN ZIMAN, AURORA POLICE CHIEF, SAYING: "At this time, we aren't sure of the motive of this act of violence." Police say it's not yet clear whether it was a premeditated attack or spontaneous, or why his job was terminated.
It's also not clear if he already had the revolver on his person when he was fired, or if he had gone to retrieve it.
The Chicago Sun-Times newspaper reported that a woman -- who identified herself as Martin's mother -- said Martin had been quote, "stressed out" in the last few weeks.
One of his neighbors has also reportedly described him as a loner, who often sat alone on his porch past midnight, and never talked about his life.
He's known to have been convicted in 1995 of aggrevated assault, a felony.
Felons are not allowed to buy firearms. The bloodshed came a day after the one year anniversary of the Marjory Stoneman Douglas High School massacre.
Mass shootings in the United States have become almost commonplace.