(CNN) The gunman at the Illinois manufacturing business where five employees were killed and five police officers were wounded was being let go by the company, Aurora Chief of Police Kristen Ziman told reporters Friday night.

The shooter, 45-year-old Gary Martin, used a Smith & Wesson handgun, the chief said. He was killed after police found him attempting to hide and he fired on officers. The chaos at the workplace lasted 90 minutes, Ziman said.

Five Aurora police officers and one employee suffered non-life-threatening injuries, Ziman said.

The first 911 calls came to Aurora police around 1:24 p.m. CT, with callers saying there was an active shooter at the Henry Pratt Company, which says it is one of the United States' largest manufacturers of industrial valves.

An employee at the company, John Probst, told CNN affiliate WLS the shooter was a co-worker and had a pistol with a laser sight.

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