The gunman, whom authorities identified as Gary Martin, 45, was killed in an exchange of gunfire with officers.
His sister, Tameka Martin, said Gary Martin had worked at the Henry Pratt Co.'s industrial warehouse for about 20 years before he was let go two weeks ago.
Others — the number remained unclear late Friday — were wounded in the shooting at the company’s warehouse, where valves and control devices used in water and power systems are designed.
Scores of law enforcement authorities swarmed the facility in Aurora, west of Chicago, sections of the city were cordoned off, and schools were forced to keep students inside for more than an hour.
By late Friday, officials had not yet provided the names of the people who were killed. Four hospitals reported treating at least seven people who were hurt. Among the wounded were five police officers who were shot and a sixth officer who was injured responding to the gunfire inside the warehouse. The wounded officers were in stable condition.
The first calls of a shooting at the warehouse began pouring in at 1:24 p.m. local time, Kristen Ziman, Aurora’s police chief, said. The first officers arrived four minutes later, rushing in and immediately being shot at, she said. Two of the first four officers to arrive were shot.
Ziman said officers from other departments converged on the site, and teams were assembled to search for the gunman inside the sprawling, 29,000-square-foot building. When they eventually found him, she said, they shot and killed him.
John Probst, an employee who was in the building at the time, told ABC 7 Chicago that he recognized the gunman, a co-worker, “running down the aisle” with a pistol that had a green laser attached to it.
He saw one person who was shot and “was bleeding pretty bad.” He believed there were others who had been shot in the office. He said he and another co-worker ran out the back door, and he heard more shots once he was outside.
Officials of the Henry Pratt Co. did not respond to inquiries Friday night. Employees reached by phone Friday night said they had been told not to comment. The company, founded in 1901, has its headquarters in Aurora, according to its website, and also has manufacturing facilities in Washington state and Indiana.
Tameka Martin said she had seen her brother a few days ago at a dinner at her mother’s house, and she described him as “very depressed, very depressed.” She added, “He really didn’t say too much to me.” Gary Martin’s family members met with officers at the Police Department late Friday; some embraced and wept.
For hours Friday afternoon, a chaotic scene played out in Aurora, a city of 200,000 residents about 40 miles west of downtown Chicago, as firetrucks, ambulances and police squad cars jammed the neighborhood of houses and warehouses.
Worried parents waited as local schools — including one not far from the warehouse — ordered students to shelter in place for more than an hour. Officers searched the blocks around the warehouse. Rescue officials stood by waiting to carry more patients to hospitals. And officials from the coroner’s office were called.
“It’s a shame that mass shootings such as this have become commonplace in our country,” said Mayor Richard Irvin of Aurora. “It’s a shame that a cold and heartless offender would be so selfish as to think he has a right to take an innocent life.”
By evening, political leaders from around the nation began issuing news releases and posting messages on social media offering sympathy and support.
The White House said that President Donald Trump had been briefed on the situation and was monitoring it. J.B. Pritzker, the new governor of Illinois, traveled to Aurora and praised the police officers who ran inside during the shooting.
“You rushed toward danger, and in doing that you saved countless lives,” Pritzker said.
Rosalee Andrada, 54, lives in a house on Cleveland Avenue, only steps from the building where the shooting took place. She had just taken her daily medication when she heard sharp staccato sounds coming from outside.
“I thought it was just ice cracking,” she said.
But her husband, Jose, hustled her and their husky, Rocky, into the basement. She said she heard five shots in total.
Rocky was anxious and wanted to come upstairs, she said, so they climbed the basement steps and looked through the kitchen window. Countless police officers had converged on the scene, a cacophony of lights and sirens.
She saw three officers helping a wounded colleague, who held his hand to his neck.
“They were carrying out their brother,” she said.
This article originally appeared in The New York Times.