ABC News affiliate, 23ABC News, are reporting that the shooter in Taft high school has been apprehended by police.
The station reported that students called the station from inside the school, whilst they were hiding.
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Guillier conceded a "severe defeat" defeat to his supporters as the result came in.
The outage struck Hartfield-Jackson Atlanta International Airport at around 1pm local time, stopping all outgoing flights.
It will be a chilly day for many parts with the highest temperatures, about 10 Celsius (50F) in the far northwest.