Aurora Police Chief Kristen Ziman said the gunman, identified as Gary Martin, 45, was an employee at the industrial complex.
“We have an active shooter incident at 641 Archer Av. This is an active scene. Please avoid the area,” the Aurora Police Department said in a tweet shortly after 2 p.m. local time, adding that additional details would be forthcoming.
The city of Aurora, which is roughly 50 miles west of Chicago, tweeted about an hour later that a suspect had been arrested.
“EMERGENCY UPDATE | 3 p.m. local time THE SHOOTER HAS BEEN APPREHENDED! The area is still on lock down! More information will be provided soon,” the city said.
At least one person was killed in the attack, a spokesman for the Kane County Coroner said.
Four police officers and several civilians were wounded in the attack, Illinois Fraternal Order of Police State Lodge President Chris Southwood said in a written statement.
Two of the people injured in the shooting were taken to Rush Copley Medical Center in Aurora where they are being treated for non-life-threatening injuries, hospital spokeswoman Courtney Satlak said in an email to Reuters.
The wounded police officers were in stable condition at a local hospital, Clayton Muhammad, spokesman for the City of Aurora, told the local ABC affiliate.
Video on local media showed numerous police cars surrounding a large commercial building in Aurora, the ground covered in snow.
Witness John Probst told CNN in an interview that he saw the gunman, a co-worker, running down an aisle of the manufacturing facility with a pistol equipped with a laser sight. Probst told the network that he saw people bleeding.
West Aurora School District 129 said on Twitter that all students in the district were being held in a “soft lockdown” on direction of the county sheriff.
A spokeswoman for U.S. President Donald Trump said that he was aware of the incident.
“The President has been briefed and is monitoring the ongoing situation in Aurora, IL,” Sarah Sanders said in a written statement.
