AURORA, Ill. — A gunman stormed through a manufacturing warehouse in suburban Chicago on Friday afternoon, killing five people inside and injuring others, including five police officers who were responding to 911 calls.

Scores of law enforcement authorities swarmed Aurora, Ill., west of Chicago, sections of the city were cordoned off, and schools were forced to keep students inside for more than an hour.

After a tense period of waiting, as officers from departments all over the region gathered near the industrial complex and crouched in small clusters, the Aurora Police Department reported that the gunman had also died after exchanging fire with police.

Authorities identified the gunman as Gary Martin, 45, and his relatives said he was a former worker in the warehouse at the Henry Pratt Co., where valves and control devices used in water and power systems are designed.

Martin had worked there for about 20 years, his sister, Tameka Martin, said in an interview, but had lost his job two weeks ago. Tameka Martin said she had had dinner with her brother a few days ago, and he had seemed “very depressed.’’ Martin and other family members, several of whom wept and embraced, met with police officers Friday evening.

By late Friday, officials had not yet provided the names of the people who were killed, and the number of people injured was still uncertain. 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.

“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 Trump had been briefed on the situation and was monitoring it.