Many who reportedly waited up to 10 hours for their gate opening, took to social media to complain about disrupted journeys, sharing images, according to some posts, of the "pandemonium" at Heathrow airport.
Heathrow staffers found themselves using white marker boards and even paper stickers to make timely updates for passengers about travel details as monitor screens went black.
A reason behind the total telecommunications outage of the Heathrow system reportedly remains unknown. The Heathrow airport tweeted regarding what they referred to as "technical issues" and apologized for the inconvenience, while vowing to fix the problems.
The major failure also prompted disruptions with baggage as hundreds of travelers were stranded in planes or in the terminal waiting for luggage that never came. Check-in systems were inaccessible for airport staffers and passengers. Thousands of disgruntled travelers missed flights amid Sunday's Heathrow airport chaos.