Michigan Attorney General Bill Schuette will soon announce felony charges against three people for the lead contamination of drinking water in Flint, local media reported Tuesday evening.

Citing anonymous sources, Detroit’s ABC affiliate WXYZ said the charges would be announced by Schuette and other local and state officials at 1 p.m. EDT Wednesday.

The three as-yet-unnamed individuals were identified following a monthslong investigation of how residents in the struggling Rust Belt city were exposed to drinking water containing harmful levels of the toxic metal linked to all manner of illness.

Up to 12,000 local children may have been exposed to harmful levels of the metal dating back to April 2014, when city officials switched water sources as a cost-cutting measure.

The switch led to water with higher levels of acidity, which corroded lead-based pipes used to deliver water to older homes. Residents had begun complain about the color and taste of the water, and initially city officials declared it was safe to drink. It wasn’t until a General Motors plant complained that the water was corroding car parts that officials looked closer at the acidity factor.

Later, the city of Detroit offered to reconnect Flint to its system and waive a $4 million fee, but local officials declined the offer. Officials also downplayed complaints from locals over the taste, smell and color of the water flowing out of their taps.

Early last year, evidence of high lead levels began trickling out, but officials didn’t issue a safety warning until October, when the city switched back to Detroit water. It took two more months for city officials to declare an emergency as the state launched an investigation. In January, President Barack Obama declared a state of emergency in Genesee County, which includes Flint.

Flint was made famous in the 1989 Michael Moore documentary “Roger & Me” about the effects of auto factory closures on the city of about 100,000 residents. The city has continued to struggle economically. Flint has a African-American majority, and the water contamination crisis led to a larger examination into negligence and mismanagement of public resources in largely minority communities nationwide.