A man about to go to prison for stealing engine parts at the factory where he had worked forced his way into the plant near Chicago yesterday and opened fire, killing four people before taking his own life.
Four others were wounded, two of them critically, in the latest of a continuing plague of violent attacks at work, in schools and in other public places in the United States.
Yesterday's attack occurred at an engine manufacturing plant operated by International Truck and Engine Corp., a subsidiary of the Navistar International Corporation, in Melrose Park just west of Chicago.
Federal officials identified the man who did the shooting as William Baker (66), of Carol Stream, another western suburb. Baker, a former employee of the company, was charged in September 1999 along with five others with conspiracy to commit theft, according to Ms Beth Needles, a spokeswoman for the US attorney's office in Chicago.
He had pleaded guilty to the charge in November 2000 and had been sentenced to five months in jail followed by five months of home confinement. She said he was scheduled to report to prison today.
The theft ring, which also involved two people who owned a trucking business, dealt in truck engine parts, she said. The plant manufactures diesel engines for trucks and buses.
Mr Rod Serpico, mayor of the blue collar suburban community, said police had told him the gunman was carrying an AK-47 rifle when he walked onto the factory floor in an area that is controlled.
The company identified two of the dead as a supervisor, Daniel Dorsch (52), and a technician, Robert Wehrheim, (47).
The injured included a 24year-old man in critical condition and a 26-year-old man in fair condition. A 45-year-old man was also in critical condition with wounds to his back and abdomen, and another man was shot in the foot.
News of the shooting quickly spread through the plant, which employs 1,400, prompting workers to flee. The facility was later closed for the day.