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

The National Guard arrived in Flint on Wednesday to help distribute bottled water and filters to some 30,000 households amid a mounting outcry against Michigan Gov. Rick Snyder’s response to a full-blown public health crisis.

Flint’s piped water became contaminated with high chloride levels when the city, in a bid to cut costs, switched its supply source in 2014 from pre-treated Lake Huron water to the Flint River. For more than a year, Flint River water “leached lead” from old pipelines into people’s homes, according to news reports, resulting in a rash of health problems for residents.

Snyder, having ignored the problem for months, declared a state of emergency on January 5, and called for reinforcements to help stem the spiraling crisis.

By Friday an estimated 30 Guardsmen are expected to be assembled in the predominantly Black city of about 99,000 residents, where American Red Cross volunteers are poised to join the door-to-door distribution effort.

Flint Mayor Karen Weaver welcomed the National Guard with “open arms” while calling for federal assistance to cope with what she called a “man-made disaster.” An Associated Press report noted Wednesday that, per a gubernatorial request, the Federal Emergency Management Agency would help the state coordinate a recovery plan.

Even as officials step up their response, a spike in the number of reported cases of Legionnaires’ disease, a potentially fatal bacterial infection, is compounding the dire situation on the ground. Eighty-seven people have reportedly contracted the disease, which is similar to pneumonia and causes high fever and respiratory problems, since the city began sourcing its water from the Flint River in the summer of 2014, according to the Washington Post. Ten of those cases were fatal.

Fox reported that of the 45 confirmed cases, 47 percent lived in residences that received water from the Flint River. Health officials, however, say there is inconclusive evidence to link the disease with the water crisis.

The deepening public health crisis was made worse for many Flint residents this week when government officials vowed to move ahead with shutting off water to homes that are behind on water payments.

The city’s finance director announced Wednesday that the city would resume mailing out water shutoff notices, which had been suspended for the holiday season. In November the city sent out 1,800 mailers to past-due account holders, but has not revealed how many notices will be distributed during this latest round. Local news outlets reported that residents were “outraged” at the prospect of being billed for poisoned water.

Both the disease outbreak and the threat of possible water shutoffs add to a long list of water woes that residents in the poverty stricken city have suffered for more than a year. People began complaining of a foul odor emanating from their taps almost as soon as officials switched the water supply. Scores of children reportedly broke out in rashes, people experienced hair loss and mood changes, and many residents reported that the water they were drinking, cleaning, and bathing with was often the color of rust.

Various studies confirmed that the city’s water supply had a serious lead contamination problem. Around the same time, General Motors announced that it would cease using the “corrosive” Flint River water in its engine plant, for fear that high chloride levels would damage metals used in its production line.

And still people continued to consume the lead-poisoned water, which is known to cause permanent brain damage and serious behavioral problems in children. Failing to elicit a response from city officials, citizens began organizing among themselves to stock and distribute bottled water and filters. But this was a huge burden on residents, 41 percent of whom live below the poverty line, according to U.S. Census data.

Numerous sources, including the Michigan chapter of the American Civil Liberties Union, have documented the lengths to which state officials went to cover up the disaster, with the Flint Water Advisory Task Force referring to the Michigan Department of Environmental Quality’s (MDEQ) response to residents’ complaints as “one of aggressive dismissal, belittlement, and attempts to discredit … the individuals involved.”

Snyder’s announcement of a state of emergency came a full three weeks after newly elected Weaver had made a similar declaration on December 14, 2015.

Beleaguered residents are now calling for Snyder’s resignation, with many claiming that his efforts over the past weeks are too little, too late. A Change.org petition urging the governor to leave office has garnered more than 700 signatures within a week.

Other commentators are calling the situation a case of environmental racism. Some 56 percent of Flint’s population identify as Black, according to Census data, which some say contributed to the state’s lethargic response to the crisis.

“I don’t think this problem would have been handled this way had it been Grand Rapids in Western Michigan or any of the other small towns that are predominantly white where their representatives hear them when they cry,” Rochelle Riley, a columnist for the Detroit Free Press, said in an interview with NPR. “You’ve got residents who have been complaining about this water after it started to flow out of their taps slightly brown and tasting funny, and nobody cared.”