MADISON, Wis. (AP) -- Authorities say the conditions of three workers shot by a colleague at a Wisconsin software company are improving.
UW Health said Friday that the three patients have been upgraded from serious to fair condition at University Hospital in Madison. Police say the woman and two men were shot Wednesday morning when a co-worker opened fire inside WTS Paradigm in Middleton.
The gunman has been identified as 43-year-old Anthony Tong. He was fatally shot by police responding to the incident.
A fourth employee suffered a graze wound during the attack .
Middleton Police Chief Chuck Foulke says investigators still don't know what prompted the attack. Tong had worked at WTS Paradigm since April 2017 and had no criminal history in Wisconsin.
Police don't know if the victims were targeted or shot at random.