The Houston Independent School District, the largest public school system in Texas, closed school buildings and district offices today because the City of Houston issued a boil-water notice, the New York Times reports.

City officials said that a power outage at a water purification plant caused water pressure to drop and triggered a mandatory boil-water notice.
“The state of Texas is immediately responding and deploying support to Houston as they work to get a safe supply of water back online,” the paper quoted Gov Greg Abbott as saying in a statement. “We urge those that the boil-water notice affects to continue heeding the guidance of local officials and take adequate precautions.”
Houston’s mayor, Sylvester Turner, said a “complete diagnostic review” of the water purification system was underway, the Houston Chronicle reported. “Two transformers went offline due to a ground trip,” at about 10:30 AM Sunday, he was quoted as saying. “A bad cell was found.”
He said the pressure came back online after just a few minutes, and officials took more than 25 water samples. Those samples must sit for at least 18 hours before being tested for contaminants. Testing is expected to begin about 3 AM Tuesday, after which the city may rescind the boil-water notice.
“It is our hope that we can get positive word late tonight or early tomorrow morning,” the mayor said Monday.
Schools in Houston were closed out of an abundance of caution, even though the water may not have been contaminated.
🚨Due to the Boil Water Notice issued by the City of Houston late this evening, all Houston ISD schools, offices, and facilities will be closed Monday, Nov. 28, 2022. #HISD will closely monitor the situation and provide additional updates regarding operations tomorrow.
— Houston ISD (@HoustonISD) November 28, 2022
Baltimore City Public Schools switched to using bottled water for drinking and food preparation in September, when E. coli bacteria was detected in the water from taps in west Baltimore.