The new mayor of Flint, Michigan, declared a state of emergency earlier this week, the latest development in the embattled city’s ongoing battle with elevated levels of lead in its water.

Karen Weaver, who became mayor in November, said in a statement on the city’s website that she made the declaration to raise awareness that the water still isn’t safe to drink, almost two months after the city stopped taking problematic water from the Flint River and reverted to its old supplier, the city of Detroit. Weaver said Flint was experiencing “a man-made disaster.”

“It’s been going on for over a year now,” Weaver said in a televised interview on The Rachel Maddow Show. “We have problems with our infrastructure. We have children that have been damaged by this lead. They have permanent brain damage. We know that Flint is not in a position to bear this burden alone, and we are asking and looking for state and federal assistance. The only way we were going to have this happen was to declare a state of emergency.”

According to MLive.com, which covers news in Michigan, the problem started in April 2014. That’s when the city stopped taking water from Detroit and started taking water from the Flint River as it awaited the construction of a new pipeline to Lake Huron. City officials decided not to ink a short-term contract with Detroit, which gets water from the lake, and use the river instead.

But in her interview with Rachel Maddow, Weaver said that the river water was corrosive and damaged a protective part of the city’s pipes, allowing lead to leach out into the water supply. Michigan Radio reported that city and state officials continued to insist the water was safe, even as scientists from Virginia Tech found higher levels of lead in the city’s tap water. MLive.com reported the city finally issued a lead advisory in September 2015, 17 months after the switch.

The city reverted to Detroit’s water system in October, but the danger of lead exposure is still very much real. The problem is no longer with the water source, but Flint’s damaged pipes.

“We don’t want people to feel that because we’ve made the switch back to Detroit water that everything is fine now, because it’s not,” Weaver said in her interview with Maddow.

The World Health Organization, an arm of the United Nations, says that lead poisoning is particularly harmful to children. It’s known to damage nervous and reproductive systems, as well as cause high blood pressure and anemia. If enough lead gets into the blood of children, it can lead to irreversible consequences like learning disabilities, retardation and even death.

In September 2015, the day before the city issued the lead advisory, doctors from the Hurley Medical Center released a study that found that more of Flint’s children were displaying elevated levels of lead in their blood since the switch. The percentage of children with elevated lead levels went from 2.1 percent to 4 percent citywide, though it was as high as 6.3 percent in some areas.

Speaking to British newspaper The Guardian on Thursday, one of the doctors responsible for that study, Mona Hanna-Attisha, said up to 15 percent of children in certain parts of the city now have high levels of lead in their blood. Hanna-Attisha called the water situation “an emergency” and said it was “a disaster right here in Flint that is alarming and absolutely gut-wrenching.”

“We are assuming that the entire population of the city of Flint has been exposed, if you drank the water or cooked with the water,” Hanna-Attisha told the newspaper, noting that cooking with the water would actually concentrate the levels of lead. According to Flint’s website, the levels of lead “remain well above” federal safety standards for drinking water “in many homes.”

In her interview with Maddow, Weaver said some kids under the age of six have neurological damage, and the city would have to attempt to provide services to them and their families.

The city encourages residents to keep using water filters while it works on a long-term solution.