(CNN)A gunman shattered a regular work day at the Molson Coors complex in Milwaukee on Wednesday, killing five co-workers before he turned the gun on himself.
Here's what we know:
Investigators have not released any details on the shooter's motive. The company describe him as an "active" employee but did not provide additional details.
Authorities have not provided the victims' identities because some family members were coming from out of town. Their names will be released in 24 to 48 hours, after their relatives have been notified, police said.
"There are five individuals who went to work today, just like everybody goes to work. And they thought they were going to go to work, finish their day and return to their families. They didn't and tragically they never will," Mayor Tom Barrett said Wednesday afternoon.
The company did not identify the 51-year-old shooter, but said he was an "active" employee at the Molson Coors complex. All the people who died Wednesday were employees, and were found in the same building, police said.
More than 1,000 people were working at the campus when police received reports of a shooting at 2:08 p.m. local time Wednesday, police Chief Alfonso Morales said. The complex includes a mix of corporate offices and brewing facilities.
When police arrived at the scene, they screened employees and checked them off one by one before securing the area hours later and allowing them to go home, CNN affiliate WITI said.
Fire dispatch audio described a chaotic scene with first responders calling it a "war zone."
Wisconsin Lt. Gov. Mandela Barnes said the incident marks the 11th mass shooting in Wisconsin since 2004.
"We are here on the scene of another American tragedy. Another senseless American tragedy. One that shouldn't have to happen and unfortunately it's in our backyard. And I hate to say that it is in our backyard once again," he said.