FILE - In this Jan. 25, 2016 file photo, third-grader Mayae Carradine listens to her teacher as she looks through a line of bottled water at Durant-Tuuri-Mott Elementary School, in Flint. In response to the city's lead-tainted water crisis, the school hands out bottles of water to students daily. Responding to the crisis in Flint, Michigan, school officials across the country are testing for lead in the water flowing from classroom sinks and cafeteria faucets to reassure anxious parents or take action if they are surprised by the results. (Jake May/The Flint Journal-MLive.com via AP) LOCAL TELEVISION OUT; LOCAL INTERNET OUT; MANDATORY CREDIT
FILE - In this Jan. 25, 2016 file photo, third-grader Mayae Carradine listens to her teacher as she looks through a line of bottled water at Durant-Tuuri-Mott Elementary School, in Flint. In response to the city's lead-tainted water crisis, the school hands out bottles of water to students daily. Responding to the crisis in Flint, Michigan, school officials across the country are testing for lead in the water flowing from classroom sinks and cafeteria faucets to reassure anxious parents or take action if they are surprised by the results. (Jake May/The Flint Journal-MLive.com via AP) LOCAL TELEVISION OUT; LOCAL INTERNET OUT; MANDATORY CREDIT

Two state regulators and a Flint employee were charged Wednesday with evidence tampering and other felonies and misdemeanors, for the first time raising the lead-tainted water crisis in the Michigan city to a criminal case.

Months after officials conceded that a series of bad decisions had caused a disaster, charges were filed against a pair of state Department of Environmental Quality employees and a local water treatment supervisor and stem from an investigation by the Michigan attorney generalโ€™s office.

For nearly 18 months, the financially troubled city of Flint, where the majority of residents are black, used the Flint River for tap water as a way to save money โ€” a decision made by a state-appointed emergency manager โ€” while a new pipeline was under construction. But the water wasnโ€™t treated to control corrosion. The result: Lead was released from aging pipes and fixtures as water flowed throughout the city of 100,000 residents.

Gov. Rick Snyder, a Republican, didnโ€™t acknowledge the problem until last fall when tests revealed high levels of lead in children. A task force appointed by the governor recently said the crisis was a โ€œcase of environmental injustice.โ€

Flint played a key role in the Democratsโ€™ presidential nomination race in March, when Michigan held its primary, with Hillary Clinton and Bernie Sanders debating in Flint and taking turns lambasting the Snyder administration.

State Attorney General Bill Schuette planned to hold a news conference Wednesday to discuss the criminal charges.

Michael Prysby, a DEQ district engineer, and Stephen Busch, who is a supervisor with the DEQโ€™s Office of Drinking Water, were both charged with misconduct in office, conspiracy to tamper with evidence, tampering with evidence and misdemeanor violations of water law.

Theyโ€™re both accused of failing to order chemicals to control corrosion. Michigan environmental regulators have acknowledged misreading federal regulations and wrongly telling the city that the chemicals were not needed.

Flint utilities administrator Michael Glasgow also was charged Wednesday with tampering with evidence for changing lead water-testing results and willful neglect of duty as a public servant.

Busch is on paid leave after being suspended earlier. Prysby recently took another job in the agency. Glasgow testified at a legislative hearing that Prysby told him phosphate was not needed to prevent lead corrosion from pipes until after a year of testing.

Flint has been under a state of emergency for more than four months, and people there are using filters and bottled water.

In addition to the lead contamination, outside experts also have suggested a link between the Flint River and a deadly Legionnairesโ€™ disease outbreak. There were at least 91 cases, including 12 deaths, across Genesee County, which contains Flint, during a 17-month period. That represents a five-fold increase over what the county averaged before.

State officials were slow to respond to expertsโ€™ and residentsโ€™ concerns. After the crisis broke open, DEQ Director Dan Wyant and his spokesman, Brad Wurfel, resigned. Snyder announced the firing of Liane Shekter Smith, the former chief of the DEQโ€™s Office of Drinking Water and Municipal Assistance.