Geek
A spokesperson for American Airlines confirmed the issue was with the Sabre flight reservation and booking system, used by several major airlines — including WestJet, Alaska Airlines and JetBlue, which are all reporting issues. http://www.waytoimprove.net/several-major-us-airlines-are-reporting-flight-check-in-issues/
Travel life
Medium - Airline Consolidators
CNN
The Guardian - Rachel Dixon
thepointsguy.com - Alberto Riva