The first outbreak started in June 2014 with 45 cases. And, emails show the Genesee County Health Department assumed the cases were connected to the new water source, the Flint River.
So, the Department of Health and Human Services told FOX 47 News the state got involved that fall.
"We were looking at the water source in homes and to see who was on City of Flint water, which facilities were on City of Flint water, where people may have been exposed," spokesman Angela Minicuci said.
But, at the same time, the Department of Environmental Quality was pushing back against the Genesee County Health Department's warnings, saying there wasn't enough evidence.
During the second outbreak between May and October 2015, just two months after the email conversation between the DEQ and County Health Officials, four more people died.
Four deaths Virginia Tech's Dr. Marc Edwards believes could've been prevented.
"They could've installed corrosion control, they could've increased the level of chlorine throughout the system," the Professor of Civil and Environmental Engineering explained. "This all goes back to the decision to not follow federal law and install corrosion control, which is their job."
But, the state still isn't completely sure the two are linked.
Minicuci explained, "It's tough to say without knowing clinically and scientifically what the cause is, what could've been prevented."
Regardless, Dr. Edwards said the DEQ should've known.
"It was very disconcerting to read those emails that just dismissed this hypothesis and called it irresponsible, when they could've been honest and steps could've been taken to prevent those deaths in 2015," he said.
One more reason why the people of Flint remain worried about their health.
Resident Lequince Morgan said, "My son could get it, we all could get it, everybody in the city can get it. Pretty sure everybody's scared and nervous."
Including the four deaths, there were a total of 42 new cases of Legionnaires' Disease during the 10-month delay of March 2015 through January 2016.