For the first time since COVID-19 brought air travel to a standstill, the number of people streaming through U.S. airport-security checkpoints over a holiday weekend exceeded pre-pandemic levels. The summer travel season ended on a busy note as more than 8.7 million people passed through security in the last four days, topping the Labor Day weekend of 2019. The Transportation Security Administration said Tuesday that that is the first time that’s happened. After a summer plagued with delayed and canceled flights, the weekend was relatively smooth. Airlines canceled less than 1% of all flights, which is less than one-third the cancellation rate registered over the summer.