More air traffic controllers – who are working without pay amid the ongoing government shutdown – have called out sick. The FAA is now warning of staffing shortages. --- Subscribe to ABC News on YouTube: https://abcnews.visitlink.me/59aJ1G ABC News Digital is your daily source of breaking national and world news, exclusive interviews and 24/7 live streaming coverage. Download the ABC News app for the latest headlines and alerts: https://abcnews.go.com/devices Watch 24/7 coverage of breaking