As the ninth day of the government shutdown wears on, the focus is on how many air traffic controllers show up to work tonight.

Concerns over flight delays and missed paychecks due to the US government shutdown escalated Wednesday, as senators rejected yet another bid to end the standoff.

“Air traffic controllers are going to do everything they can to show up to duty, save people’s lives, and do the job that we do day in and day out,” National Air Traffic Controllers Association Presi...