CHICAGO (CBS) –A fatal shooting incident in a commercial district in Bolingbrook prompted authorities to order a lock down at four schools on Monday.

Police confirmed reports of a shooter on Veterans Parkway, near Remington around 9:40 a.m. When police arrived at auto parts supplier YCB International in the 600 block of Veterans Parkway, they found two men dead. WBBM Newsradio has been told that one of those dead was an employee.

Sources told CBS 2 that police are investigating the shooting as a murder suicide. The gunman, sources said, did not work at YCB.

The Will County Coroner’s Office identified the dead men as Xinling Zhang, 39, of Naperville, and Degang Zhang, 48, of Aurora.

“There were actually three employees on the scene at the time,” said Bolingbrook Police Lieutenant Carter Larry. “We have found two deceased. We did recover a gun on the premises as well.”

Two employees were not hurt, and are being questioned by police about what they saw.

Four schools–Bolingbrook High School, Addams Middle School, and Independence and Oak View elementary schools–were on “soft lock down” for about an hour as a precaution.

A soft lock down means all doors are locked and no one was allowed to enter or leave the buildings. Normal activities continue inside the building.

The lock down was lifted around 11 a.m., officials said. It was lifted quickly, but will leave a lasting impression on workers in nearby buildings.

“It’s just something you can’t prepare for,” said Jennifer Rasi, who works nearby. “God only know if they walked in our building. It’s scary.”