The absence rate at TSA on Monday is 7.6 percent, up from 3.2 percent on the same day last year, according to TSA spokesperson Michael Bilello.

Major airports in cities such as Atlanta and Houston “are exercising their contingency plans to uphold aviation security standards.” That means condensing TSA officers into fewer checkpoints and screening lanes to uphold security standards at the cost of longer lines.

Queues at Atlanta Hartsfield-Jackson International Airport security extended more than an hour long on Monday morning, causing travelers to miss flights, according to ABC-affiliate WSB.