Michigan's attorney general announced Wednesday that the head of the state's health department and four others have been charged with involuntary manslaughter for their role in the years-long Flint water crisis.

Nick Lyon, director of Michigan Health and Human Services, "failed in his responsibilities to protect the health and safety of the citizens of Flint," state AG Bill Schuette said at a press conference Wednesday.

A press statement from Schuette's office alleges that Lyon waited a year before alerting the public about the outbreak of Legionnaires' Disease as a result of the crisis, an act that led to the death of 85-year-old Robert Skidmore. He also thwarted an independent researcher from investigating the cause of the outbreak, the statement says. 

Lyon was also charged with misconduct in office.

The others now slapped with involuntary manslaughter charges are former Flint Emergency Manager Darnell Earley; former City of Flint Water Department Manager Howard Croft; Michigan Department of Environmental Quality's Drinking Water Chief Liane Shekter-Smith; and Water Supervisor Stephen Busch.

Those four, the Detroit News reports, "had been charged with less-serious crimes during the past year."

NPR writes: "More than a dozen former state and city officials have been criminally charged in connection with the Flint water crisis," and thus far, "Lyon and Wells are the highest-ranking state officials to be charged."

According to Lonnie Scott, executive director of advocacy group Progress Michigan, the new charges stemming from Schuette's investigation "show that the failure in Flint lies squarely at the feet of Governor Rick Snyder."

"Now that these charges have been levied against a top cabinet official, we renew our call for Governor Rick Snyder to immediately resign," Scott added

Yet Snyder, who on Wednesday offered a statement in support of Lyon and Wells, continues to evade accountability.

The Washington Post reports:

Schuette on Wednesday addressed the pressure he has gotten to charge Snyder, who has heard repeated calls to resign for his appointment of emergency mangers in Flint and the state's delayed and inadequate response there.

"We only file criminal charges when evidence of probable cause to commit a crime has been established," Schuette said. He later revealed that investigators have been unable to speak with Snyder about his role in the catastrophe. "We attempted to interview the governor. We were not successful," he said.

The announcement of the new charges comes a day after Flint activists delivered over 1,000 water bottles to the office of Snyder, each filled with a letter from a Flint resident saying what he or she feels is owed by the governor as a result of the water crisis. One message read: "you owe me clean water and money if not, you schould [sic] go to jail"