However, no announcements about the outbreak were made then, and two months later a Michigan state health official declared it over, the newspaper reported based on emails by local, state and federal officials it reviewed. The disease would kill four more people in the summer and not be brought to public attention until January 2016.

The predominantly black city of some 100,000 people was under control of a state-appointed emergency manager in 2014 when it switched its source of water from Detroit's municipal system to the Flint River.

Flint switched back to Detroit water in October after tests found high levels of lead in samples of children's blood. The more corrosive water from the river had caused lead to leach out of the pipes into the drinking water, officials said.

Lead can cause permanent developmental delays and learning difficulties in children. Blood lead levels in some children in the city more than doubled, it was found in 2015. Several lawsuits have been filed by parents who say their children are showing dangerously high levels of lead in their blood.

Even after Flint went back to using Lake Huron as its source for drinking water, the city found in December that water lead levels were still “well above” the acceptable federal level in many homes. Bottled water was handed out by the National Guard, and activists and celebrities including Cher and rapper Meek Mill have also donated money and bottled water in lieu of sufficient state and federal action.

Residents and protesters have called on Michigan Gov. Rick Snyder to step down over his handling of the water crisis and the Legionnaires' disease outbreak — which he said that he alerted the public to on Jan. 13 and that he had only heard about it two days earlier.

Snyder said in a Friday statement in which the state released emails and other documents from several state departments that "all levels of government failed the people of Flint. This crisis never should have happened." He said by making the documents public, anyone could review them.

Earlier this month, liberal group Progress Michigan released emails allegedly indicating that high-ranking state officials knew about an increase in Legionnaires' disease in Genesee County, where Flint is located, and a possible link to the contaminated water almost a year before the governor said he got information about the outbreak.

Also on Friday, the Flint fire and police chiefs resigned in what the city’s mayor, Karen Weaver, called a first step in restructuring operations as Flint struggles to cope with dangerous levels of lead in its drinking water.

"Mayor Weaver has determined the city needs fresh faces in place with new ideas to help move Flint forward," a statement from her office said.

Chief of Police James Tolbert and the fire department chief, David Cox Jr., submitted their resignations to Weaver, the statement said.

The mayor's statement Friday didn’t mention the water crisis. It said the departments would be headed police Captain Colin Bernie and Fire District Commander Stephen Cobb while a search is conducted for permanent replacements.

Al Jazeera and Reuters