Read more of our articles on Flint’s water emergency here.

The Mayor of Flint, Michigan, declared a state of emergency on Monday, citing dangerously high levels of lead in children’s blood caused by the city’s water supply.

Flint residents have for months implored city officials to act, complaining that the cloudy, foul-smelling water was causing a host of preventable problems, including skin lesions, hair loss, chemical-induced hypertension, and chronic respiratory disorders.

In a statement, Mayor Karen Weaver described the crisis as a “Manmade disaster” that began when the city switched its water source from the Detroit system to the Flint River in 2014. The move was meant to save the city about $5 million and serve as a temporary fix until a pipeline to Lake Huron’s Karegnondi Water Authority was built.

Then-Mayor Dayne Walling celebrated the switch, telling local media outlets that “the water quality speaks for itself.”

But the city did not adequately treat the river water, reports say, which then ate away at aging pipes throughout the city. Lead leaked into the water supply and toxins flowed from residents’ taps and faucets. Avoiding tap water became a way of life, as the Detroit Free Press reported. Residents who could afford it bought bottled water with which to drink and cook; others boiled pots of tap water to fill tubs or gave children baths with baby wipes.

City and state officials “regularly assured the Flint water users that the water supplied from the Flint River was being properly treated, monitored and tested and was safe to consume and use,” according to a complaint filed in a class action suit against city and state officials in November.

Then doctors from a local medical center presented findings that confirmed residents’ fears: the proportion of children younger than 5 years old with elevated levels of lead in their blood had risen sharply after the water source changed. The doctors noted that high levels of lead can lead to a decrease in IQ, an increased likelihood of ADHD and “delinquent behaviors”, and a host of other cardiovascular, immunogenic, and endocrine disorders.

The Centers for Disease Control and Prevention (CDC) estimates there are 4 million households nationwide in which children are exposed to high levels of lead.

Weaver in her emergency statement said the damage to children in the city was “irreversible,” and would lead to a greater need in special education, along with mental health and juvenile justice services.

Recent census data shows that more than 40 percent of the population in Flint is living in poverty. For residents surviving on so little, purchasing gallons of bottled water to drink, cook, and wash with often presents an insurmountable challenge.

“I can’t afford the filters every single month. When you don’t have finances, and you want to eat, you take your choice. Either the water or food,” Flint resident Ronda Thorton told photojournalist Brittany Greeson, whose ongoing project “We Fear the Water” documents the city’s water crisis.

Michigan Gov. Rick Snyder in early October announced that he would reconnect Flint to the Detroit water system. The announcement came the same day that water in three local schools tested positively for high levels of lead, including Freeman Elementary School, where a sample showed lead levels almost seven times the level that requires remediation, the Detroit Free Press reported.

Water started flowing again from Detroit to Flint in mid-October.

“Flint residents need to have access to safe, clean water,” a press secretary for Snyder’s office wrote to The Washington Post. “Gov. Snyder and the administration have been working closely with the city to focus on health issues affecting children and other city residents, and address water infrastructure challenges.”

But some residents, including those who filed the class action suit, believe much of the damage has already been done.

“The deliberately false [denial] about the safety of the Flint River water was as deadly as it was arrogant,” the complaint reads.