The American city of Flint, Michigan switches its water source to the Flint River, beginning the ongoing Flint water crisis which has caused lead poisoning in up to 12,000 people, and 15 deaths from Legionnaires disease, ultimately leading to criminal indictments against 15 people, five of whom have been charged with involuntary manslaughter.

The Flint water crisis is a public health crisis that started in 2014 after the drinking water for the city of Flint, Michigan was contaminated with lead and possibly Legionella bacteria. In April 2014, during a budget crisis, Flint changed its water source from treated Detroit Water and Sewerage Department water (sourced from Lake Huron and the Detroit River) to the Flint River. Residents complained about the taste, smell, and appearance of the water. Officials failed to apply corrosion inhibitors to the water, which resulted in lead from aging pipes leaching into the water supply, exposing around 100,000 residents to elevated lead levels. A pair of scientific studies confirmed that lead contamination was present in the water supply. The city switched back to the Detroit water system on October 16, 2015. It later signed a 30-year contract with the new Great Lakes Water Authority (GLWA) on November 22, 2017.On January 5, 2016, Michigan Governor Rick Snyder declared a state of emergency in Genesee County, of which Flint is the major population center. Shortly thereafter, President Barack Obama declared a federal state of emergency, authorizing additional help from the Federal Emergency Management Agency and the Department of Homeland Security.Between 6,000 and 12,000 children were exposed to drinking water with high levels of lead. Children are particularly at risk from the long-term effects of lead poisoning, which can include a reduction in intellectual functioning and IQ, and an increased chance of Alzheimer's disease. The water supply change was considered a possible cause of an outbreak of Legionnaires' disease in the county that killed 12 people and affected another 87, but the original source of the bacteria was never found.Four government officialsone from the city of Flint, two from the Michigan Department of Environmental Quality (MDEQ), and one from the Environmental Protection Agency (EPA)resigned over the mishandling of the crisis, and one additional MDEQ staff member was fired. In January 2021, former Michigan Governor Rick Snyder and eight other officials were charged with 34 felony counts and seven misdemeanors41 counts in allfor their role in the crisis. Two officials were charged with involuntary manslaughter. Fifteen criminal cases have been filed against local and state officials, but only one minor conviction has been obtained, and all other charges have been dismissed or dropped. On August 20, 2020, the victims of the water crisis were awarded a combined settlement of $600 million, with 80% going to the families of children affected by the crisis. By November, the settlement grew to $641 million.An extensive lead service pipe replacement effort has been underway since 2016, with innovative techniques such as machine learning used to predict the number and location of lead pipes. In early 2017, some officials asserted that the water quality had returned to acceptable levels, but in January 2019, residents and officials expressed doubt about the cleanliness of the water. There were an estimated 2,500 lead service pipes still in place as of April 2019. As of December 8, 2020, fewer than 500 service lines still needed to be inspected. As of July 16, 2021, 27,133 water service lines had been excavated and inspected, resulting in the replacement of 10,059 lead pipes.

Flint is the largest city and seat of Genesee County, Michigan, United States. Located along the Flint River, 66 miles (106 km) northwest of Detroit, it is a principal city within the region known as Mid Michigan. At the 2020 census, Flint had a population of 81,252, making it the twelfth largest city in Michigan. The Flint metropolitan area is located entirely within Genesee County. It is the fourth largest metropolitan area in Michigan with a population of 406,892 in 2020. The city was incorporated in 1855.

Flint was founded as a village by fur trader Jacob Smith in 1819 and became a major lumbering area on the historic Saginaw Trail during the 19th century. From the late 19th century to the mid 20th century, the city was a leading manufacturer of carriages and later automobiles, earning it the nickname "Vehicle City". General Motors (GM) was founded in Flint in 1908, and the city grew into an automobile manufacturing powerhouse for GM's Buick and Chevrolet divisions, especially after World War II up until the early 1980s recession. Flint was also the home of a sit-down strike in 1936–37 that played a vital role in the formation of the United Auto Workers.

Since the late 1960s, Flint has faced several crises. The city experienced an economic downturn after GM significantly downsized its workforce in the area from a high of 80,000 in 1978 to under 8,000 by 2010. From 1960 to 2010, the population of the city nearly halved, from 196,940 to 102,434. In the mid-2000s, Flint became known for its comparatively high crime rates and has repeatedly been ranked among the most dangerous cities in the United States according to crime statistics. The city was under a state of financial emergency from 2002 to 2004 and again from 2011 to 2015.From 2014 to 2019, Flint faced a public health emergency due to lead contamination in parts of the local water supply as well as an outbreak of Legionnaires' disease. The acute lead crisis has been addressed as the city has secured a new source of clean water, installed modern copper pipes to nearly every home, and distributed filters to all residents who want them. However, a legacy of distrust in public authorities remains.