City officials in Corpus Christi, Texas, are warning residents not to use their tap water — at all — after possible contamination by an unknown chemical.
A press release from the city points to "a recent back-flow incident in the industrial district," and instructs residents to use just bottled water all food preparation, drinking, washing and bathing needs until further notice.
"DO NOT TRY TO TREAT THE WATER YOURSELF," the city says. "Boiling, freezing, filtering, adding chlorine or other disinfectants, or letting the water stand will not make the water safe."
Local schools have canceled classes, Corpus Christi newspaper The Caller-Times reports.
The city suspects an "oil-based petroleum chemical," city spokeswoman Kim Womack told the Caller-Times. Unnamed city officials told the paper the initial report of a "water issue" involved a refinery, which they would not identify.
More than 300,000 people live in Corpus Christi, according to the U.S. census.
Multiple stores in the region are now sold out of water bottles.