FORT ATKINSON, Wis. (CBS 58) -- More than a dozen people were transported to treatment following a carbon monoxide leak in Fort Atkinson on Monday, June 8. 

It happened at an industrial facility on Rockwell Avenue. 

According to the Fort Atkinson Fire Department, there were 150 people working at the time, when some employees reported headaches. 

The fire department responded and found high levels of carbon monoxide; the building was evacuated. 

Thirteen people were transported from the scene for treatment, and 14 additional people were evaluated at the scene. 

The cause of the leak is under investigation.