All United Airlines flights in the United States were grounded on Wednesday due to a computer issue, according to CNBC.
United told the Associated Press that the computer problems were related to "network connectivity" and that it's working to resolve the issue.
Flights that are already in the air are unaffected by the computer glitch, Bloomberg reports.
Lines of passengers are already starting at airports:
The joy that is O'Hare right now during this @united debacle. #Grounded #Ohare #Airport #ComputerGlitch pic.twitter.com/ls6N6X35G8
- Andrew Lahey (@colormelahey) July 8, 2015(Reuters editing by Alden Bentley)