Six people, including the shooter, have reportedly been killed in a rampage Wednesday at the Milwaukee campus of the Molson Coors beer company.
A police source told CBS that the gunman was fired earlier in the day, and "he returned and started shooting with a silenced gun."
According to CBS:
The MillerCoors plant is one of the most popular tourist attractions in Milwaukee. Tours of the building were in progress at the time and were also placed on lockdown, CBS 58 Milwaukee reporter Bill Walsh reported.