Clinton, who took a break from campaigning in New Hampshire to visit Flint, is the first presidential candidate to visit the city.
During her remarks today, she called the situation in Flint "immoral" and said that if a situation like this had happened in a wealthier community, "I think we all know we would have had a solution yesterday."
She called for Congress to approve a $600 million amendment to help the city.
Clinton has recently made the crisis in Flint a top issue of her campaign. Two of her aides traveled to the city last month to address the crisis. During her visit today, Clinton was also scheduled to meet with Flint Mayor Karen Weaver and other city officials.
The situation in Flint originated two years ago when high levels of lead were found in the city's water supply. Up to 12,000 children may have been exposed to the contaminated water, officials say.
On Sunday, Clinton described meeting a child affected by the water crisis here.
"I was just heartsick," she said.
She then spoke about her granddaughter, Charlotte, and said she "really could not imagine" how the people of Flint must be feeling.
A woman in the crowd yelled out, "Anger!"
"Let's make sure we take care of the people of Flint, and give every child a chance to live up to her God-given potential," Clinton said.