Residents of eight communities around Lake Jackson, Texas, were warned on Saturday not to use tap water for anything other than flushing toilets.
That's because a rare brain-eating amoeba was found in the public water supply.
The microbe, naegleria fowleri, is found in fresh water and soil. If it gets up the nose, it can cause a potentially fatal brain illness.
The CDC says symptoms include seizures, vomiting, and hallucinations — with people dying within a week of contracting the illness.
According to Business Insider, the advisory was issued after a six-year-old boy died of the illness caused by the microbe.
Late Saturday the notice was lifted, but a water boiling notice remains in place for the city of Lake Jackson where officials are decontaminating the local water supply.