One passenger posted a Youtube video that showed the line stretching through the airport, through a set of doors, around the corner, and all the way down a hallway to the CTA Orange Line stop.

Some passengers said it took an hour to get through the security checkpoint.

TSA's administrator has testified on Capitol Hill about these problems, saying that TSA lost thousands of employees and some have yet to be replaced.

By 10 p.m. Thursday, the line had returned to normal.