Hundreds of flights are canceled at O'Hare and Midway airports on Saturdays and delays are growing after an hours-long FAA nationwide ground stop on Friday.
As of Saturday morning around 9:30 a.m., airlines had canceled over 500 flights at O'Hare and over 60 flights at Midway, with nearly 360 flights delayed.
Video from inside of Terminal 1 at O'Hare Airport shows long lines as passengers attempt to get on new flights and check the status of their bags on Saturday morning.
Travelers stuck at O'Hare overnight told CBS News Chicago getting their bags has been one of the biggest issues. Many passengers have reported hours-long waits to determine if their flight would take off and frustrating error messages.
"We were stuck on the tarmac for about four hours and its been about three hour since I've been looking for my bag and i found it," Samantha Suretha, a passenger from Houston, said. "I hit the jackpot."
Another passanger said she was stuck on a plane for four hours. She called the experience "misrable" waiting for her checked bag.
A passenger traveling to make a cruise in Tampa, Florida, said she arrived at the airport at 6:30 a.m. only to find out hours later her flight was canceled.
"Thousands [of dollars] down the drain, they can only send us to Miami," Kathy McCall said.
Southwest is allowing eligible customers flying through Monday to rebook or fly standby within five days of their original travel date. Those customers can also keep their existing reservation. Some travelers may qualify for a refund.
Amtrak is also reporting an increase in demand.
The FAA and White House said the issue appeared to be caused by a "telecommunication outage." The nationwide ground stop was lifted around 7:30 p.m. Chicago time.
Everything is back up and running and a Trump transportation admin officials said while it's safe to fly, the nation must address this aging and outdated system or these types of "hiccups" could happen again.
Nationwide ground stops are exceedingly rare, and the most notorious one was issued after the September 11 terrorist attacks in 2001. But officials said Friday's ground stop was not akin to what happened on 9/11, as airplanes were not being told to land immediately at the first available airport.
Instead, this ground stop was due to problems affecting the in-route communication system: the high-altitude tracking that is done at 20 air traffic control centers across the country as well as in Alaska and Hawaii.
Passengers in the air were not in any danger during the ground stop, officials said, and there was no national security threat.
Homeland Security Secretary Markwayne Mullin emphasized as he spoke to reporters Friday evening that this was a telecommunications outage affecting the ability for air traffic controllers and planes to communicate. Transportation Secretary Sean Duffy said the ground stop was issued "out of an abundance of caution."
Mullin also said they do not have indications that what happened was the result of a cyberattack.
Even though main radio communications went down, planes were not without the ability to communicate at all. Planes, air traffic controllers, and airports use the ACARS system, which stands for Aircraft Communications Addressing and Reporting System, and has been in place since the 1970s. ACARS is essentially a VHF-based text messaging system for aircraft that allows them to send messages back and forth without using voice communication frequencies.
It's not just pilots who can use ACARS; flight crews can also use it to communicate with their airline master command centers and help get information to passengers in the air and on the ground.
