Michigan’s attorney general has filed charges against three officials over contaminated water supplies in Flint.
Two state employees in the environmental department have been charged with misleading the US government about the problem.
And a Flint employee is being charged with altering water test results.
Nearly 100,000 residents of the poor, mostly black city, were exposed to high levels of lead, sparking an outcry.
Lead exposure can cause learning disabilities and behavioural problems in children.
“They had a duty to protect the health of families and citizens of Flint and they failed,” said Michigan Attorney General Bill Schuette.