President Barack Obama on Wednesday visited Flint, as questions linger over whether his environmental regulators could have acted more urgently to address the lead poison water crisis.

Obama will get updates from federal officials on the response in Flint, a mostly African-American city where more than 40 percent of the city’s 100,000 people live in poverty. He will also listen to residents and speak at a high school during his visit, the first since the crisis came to light.

“Like you, I’ll use my voice to call for change and help lift up your community,” Obama wrote last week to Amariyanna Copeny, an eight-year-old Flint girl who has marched in protests about the crisis and had asked to meet him. 

While under control of a state-appointed emergency manager in 2014, the financially-strapped city switched from Detroit’s water system to the Flint River to save money. The more caustic water caused lead, a toxin that harms brain development, to leach from aging city pipes. 

After blood tests of children showed high lead levels, the city switched back to Detroit’s system last October but residents still must filter their water. 

The White House points out that Michigan brought charges against three state and local officials last month for misleading regulatory officials and manipulating water tests. The Michigan attorney general said more charges were to follow.

Critics say the federal Environmental Protection Agency shares blame for not reacting more urgently. Susan Hedman, the EPA’s Midwest chief, and an Obama appointee, resigned in February amid scrutiny for not acting quickly to a memo from agency scientist Miguel Del Toral in June 2015 that said tests showed high lead levels in water from Flint homes.

Last week, Flint residents filed a damage claim for $220 million against the EPA alleging that negligence led to the injuries of more than 500 people. The complaint cites a Del Toral memo that said it would border on criminal neglect not to warn Flint residents about lead contamination.

The EPA has said it will look into the complaint.

The Federal Bureau of Investigation said in February it was joining a criminal investigation with the EPA’s Office of the Inspector General and federal prosecutors in Michigan to explore whether laws were broken by a range of officials.

White House spokesman Josh Earnest has refrained from commenting at length on whether federal officials could have acted faster, citing ongoing investigations. 

The EPA, which has seen its budget squeezed by Congress, acknowledges that there are issues with its lead and copper rule that need to be addressed to prevent similar crises in other cities. The agency will propose changes to the rule early next year, it says. The rule would be finalized later, likely after Obama leaves office on Jan. 20.

After Obama declared a state of emergency in January, freeing up to $5 million in funds, officials distributed water filters, clean water, and other aid. The White House also expanded access to Medicaid and urged Congress to approve more federal aid to Flint.