FAA headquarters in Washington, DC|Matthew G. Bisanz|CC BY-SA 3.0

The Trump administration’s mass layoffs reached the Federal Aviation Administration (FAA), which saw hundreds of employees fired over the weekend.

The FAA employs around 45,000 people.

According to the Department of Transportation (DOT) Secretary Sean Duffy, all FAA personnel let go were under probation, meaning they had been at the job less than a year.

The firings received criticism from the Professional Aviation Safety Specialists (PASS) union representing FAA workers and former DOT secretary Pete Buttigieg.

The terminations come on the heels of deadly aircraft accidents that underscored the workload of air traffic controllers.