On the Dash:
- GM closed its Cole Engineering Center in Warren, Michigan, through Sept. 22 after two employees tested positive for Legionnaires’ disease.
- The facility, which employs about 10,000 people, is undergoing third-party testing, though no Legionella bacteria have been found so far.
- Health officials are investigating shared spaces as possible sources, while recent Legionnaires’ outbreaks elsewhere highlight broader public health concerns.
General Motors has closed its Cole Engineering Center north of Detroit until at least Sept. 22 after two employees tested positive for Legionnaires’ disease, temporarily idling a site where about 10,000 people work on future vehicles and technologies.
GM shut down the facility Sept. 10 after being notified by the Macomb County Health Department. The company said regular bacteria testing had not found any issues, and the building has not been confirmed as the source of the infections. Other buildings on GM’s 710-acre campus remain open, and testing of the Cole Center’s ventilation and water systems is underway.
Legionnaires’ disease is a severe form of pneumonia that can cause lung failure and death, according to the U.S. Centers for Disease Control and Prevention (CDC). While most infections can be treated with antibiotics, older adults, people with underlying health conditions, and current or former smokers face higher risks. About one in 10 cases results in death. The illness is spread by inhaling water vapor contaminated with Legionella bacteria, which can be prevented through proper disinfection of cooling towers, hot tubs, fountains, and humidifiers.
Health officials said the two employees who tested positive did not work together, and investigators are examining whether they may have shared common areas. More than 120 samples have been collected from the site, and none have tested positive for Legionella so far.
The two GM cases follow others reported in August at a nursing home in Dearborn, Michigan. Nationally, outbreaks remain a concern, such as in New York City’s Harlem neighborhood, where more than 110 people were infected and seven died earlier this year, leading the city to propose stricter testing regulations.
Testing at the Cole Engineering Center is ongoing, and results will determine next steps in reopening the facility.


