Dangerously high levels of toxins from algae on Lake Erie left 500,000 people in Toledo, Ohio, without safe drinking water on Saturday and sent many driving to other states in search of bottled water, according to The Associated Press.
The crisis affects the state's fourth-largest city and surrounding counties, forcing most restaurants and the Toledo Zoo to close, the AP reported.
Ohio Governor John Kasich declared a state of emergency for the region, freeing up resources for the Ohio National Guard and state workers to truck safe water to people who need it, according to the AP.
City officials said in a statement that Lake Erie, the source of local drinking water, may have been impacted by a "harmful algal bloom," the AP reported.
In response to the Toledo crisis, Chicago is doing additional testing on Lake Michigan water as a precaution, and expects results in a day or two, city spokeswoman Shannon Breymaier said, according to the AP.
Blue-green algae are naturally found in Ohio's lakes, ponds and slow-moving streams, the AP reported. Algal blooms in Lake Erie are fairly common in recent years, typically in the summer, state emergency operations spokesman Chris Abbruzzese said.
Potentially dangerous algal blooms, which are rapid increases in algae levels, are caused by high amounts of nitrogen and phosphorous, according to the AP. Those nutrients can come from runoff of excessively fertilized fields and lawns or from malfunctioning septic systems or livestock pens, city officials said.
Officials could not say when Toledo's water service can be declared safe, and boiling the water will not destroy the toxic microcystins, the AP reported.
Drinking the contaminated water could affect the liver and cause diarrhea, vomiting, nausea, numbness or dizziness, city officials said, according to the AP.
The water should not be used for drinking, making infant formula, making ice, brushing teeth or preparing food, the governor's office said, the AP reported. It also should not be given to pets, but hand washing is safe and adults can shower in it, officials said.
As soon as the crisis became public early Saturday, all local stores sold out of their water supplies, according to the AP. That sent residents traveling in all directions to find supplies.
Jeff Hauter of Toledo drove to a Walmart in suburban Detroit, where he bought 18 gallons and four cases of water, the AP reported. He said he ran into others from the Toledo area loading up their trucks and cars.
A retired Toledo water department employee, Hauter said the crisis did not shock him, according to the AP.
"It's a lack of preventative maintenance over many city administrations," he said. "It was inevitable."