FLINT, Mich. — Three government workers were charged with crimes on Wednesday for their roles in this city’s water crisis, accused in part of covering up evidence of lead contamination.

The workers — an employee of Flint and two state workers assigned to monitor water quality in cities — are the first to face criminal charges in connection with the failures that left residents of this city drinking foul and unsafe water for many months.

In announcing the charges, some of which are felonies carrying penalties of as much as five years in prison, Bill Schuette, the Michigan attorney general, answered skeptics in Flint and elsewhere who had openly doubted that anyone would ever be held accountable for the health crisis here.

Emails and other documents have shown a cascading series of failures at every level of government — local, state and federal — and Mr. Schuette, a Republican who is widely seen as a possible candidate for governor in 2018, emphasized that his investigation, begun in January, was far from over.