(CNN) Criminal charges against three men in Michigan on Wednesday marked a milestone in a crisis that's been years in the making , potentially harmed tens of thousands of people and cast a harsh spotlight on infrastructure issues across the country.

Mike Glasgow, Stephen Busch and Mike Prysby could face years of prison time if they're convicted. They're the first government employees to face charges tied to the Flint water crisis.

But they shouldn't be the last, according to residents of the city who had water contaminated with lead pumped into their homes.

Nakiya Wakes, who believes the contaminated water caused her to have two miscarriages , said holding three officials accountable "is a start, but only a start."

"I won't rest until the governor is charged," she told CNN.

The case is far from closed. Busch and Prysby have pleaded not guilty. Glasgow has yet to appear in court.

State Attorney General Bill Schuette told reporters that the charges "are only the beginning" of a lengthy and exhaustive probe.

"No one is above the law, not on my watch," he said.

Gov. Rick Snyder maintained that he'd done nothing wrong. "Due process," he said, will reveal whether anyone acted criminally.

"What I've said consistently from the beginning is this tragic situation was the result of bad decisions by bureaucrats. Again, I always described it as people lacking common sense. This puts it in the context of criminal behavior," Snyder said. "Was it actually criminal? Or was it poor decision-making? And again, I'm not looking for vindication. This is about getting to the truth, getting to accountability."

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'This is exactly what we were afraid of'

Two years ago, in a move to save money, the state switched Flint's water supply from Lake Huron to the Flint River, a tributary notorious for its filth . The Michigan Department of Environmental Quality failed to treat the corrosive water, which ate into the city's iron and lead pipes, causing lead to leach into the drinking water.

It's a massive public health crisis that's drawn national attention, and there's plenty of blame to go around. Already one group of investigators has concluded that government at every single level failed Flint

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Even as state authorities trumpet their push for accountability, Laura MacIntyre says she's worried they're passing the buck.

MacIntyre, a Flint resident who said the water crisis makes her fear for the safety of her three children, said it would be a "miscarriage of justice" if Snyder isn't charged. She worries that the announcement of charges represented "just two to three people who will take the fall for actions that have included many, many more people. It definitely goes much higher."

She said: "This is exactly what we were afraid of. That it would fall down to a couple of individuals."

What you should be doing is a perp walk #FlintWaterCrisis #ArrestGovSnyder https://t.co/GTtju9Mam2 — erin brockovich (@ErinBrockovich) April 20, 2016

In addition to Snyder, MacIntyre would like to see the city's former emergency manager charged for the decisions he made -- or precautions he didn't take -- in switching the drinking source.

Resident Aaron Stinson says recent tests show he has lead levels almost double what is considered toxic. He suffers from various aches and pains and he flatly blames the drinking water and those who allowed that water to arrive in his tap.

"It's all good and well to get the folks in the middle," he said, "but we all know this started at the top, and those top officials should also be charged for their role."

The accused

Schuette didn't mince words when he announced the charges against the two state employees and one city employee Wednesday.

"They failed Michigan families. Indeed, they failed us all. I don't care where you live," Schuette said.

Busch, a district water supervisor for the Michigan Department of Environmental Quality, and Prysby, a district water engineer, each face six charges.

Accusations include misleading federal regulatory officials, manipulating water sampling and tampering with reports.

Glasgow, a former laboratory and water quality supervisor who now serves as the city's utilities administrator, is accused of tampering with a lead report. He is charged with tampering with evidence, a felony, and willful neglect of duty, a misdemeanor.

He hasn't appeared in court yet to respond to the charges. But his attorney described him as "an honest, decent person who has faithfully worked for the city of Flint and its residents" for years.

His attorney, Robert Harrison, said he has not received a copy of the warrant and complaint filed against his client, and most of what he knows is what's been in the news.

"So, obviously, I cannot comment specifically about these charges," Harrison said.

In an interview with CNN last month, Glasgow alleged that Busch and Prysby told him to alter water quality reports and remove the highest lead levels.

Prysby and Busch could not be immediately reached to respond to the allegation.

An email sent April 17, 2014 -- eight days before Flint switched its water source -- seems to indicate that Glasgow had problems with the monitoring schedule and his staffing ahead of the switch.

"I do not anticipate giving the OK to begin sending water out anytime soon. If water is distributed from this plant in the next couple weeks, it will be against my direction," Glasgow wrote to state officials, including Busch and Prysby. "I need time to adequately train additional staff and to update our monitoring plans before I will feel we are ready. I will reiterate this to management above me, but they seem to have their own agenda."

Governor: Charges are 'deeply troubling'

The charges against the three men "are deeply troubling and extremely serious," Snyder told reporters.

Asked at the news conference whether he did anything criminal, Snyder replied, "I don't really want to get into that kind of speculation. I don't believe so."

In a statement released by his spokesman, Snyder said he has supported the probe and promised the state would pursue evidence of wrongdoing and hold those responsible accountable.

"The people of Flint and across Michigan are owed straight answers about how the Flint water crisis happened," the statement said.

Dozens of lawsuits filed

More than 50 lawsuits have been filed since January, though one federal class-action was dropped Tuesday over a jurisdictional issue.

The state made the decision to switch the water source, but some lawsuits accuse the city of being complicit by not doing enough during the 18 months that residents received their drinking water from the Flint River.

City employees were involved in treating water at the Flint Water Treatment Plant as well as in testing residents' water for the state.

One class-action lawsuit says residents have suffered skin lesions, hair loss, vision loss, memory loss, depression and anxiety. There are also concerns about miscarriages , imminent learning disabilities in children and Legionnaires' disease

On the mend?

Though Flint's water supply is "definitely on its path to recovery," concerns about lead and other issues hinder the cleanup of the system's corroded pipes, according to the Virginia Tech researcher who exposed the water crisis in the city of 100,000.

Professor Marc Edwards said last week that lead contamination levels continue to surpass acceptable federal standards, and he urged residents to keep using bottled or filtered water for cooking or drinking.

JUST WATCHED Governor Snyder drinks Flint water Replay More Videos ... MUST WATCH Governor Snyder drinks Flint water 01:21

"We're still drinking bottled water, using the filters to wash our hands, hoping that we're not being poisoned by the shower," MacIntyre said.

The Flint resident worries about her family, especially her three children, and she said she hasn't seen any large-scale changes in her hometown.

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"It's just been so discouraging and disheartening," she said. "We're exhausted and really nothing has changed. None of our pipes have been changed. It's like they're waiting us out ... waiting for us to quit."

Editor's note: An earlier version of this story misstated the number and nature of the charges against the three men.