*Main story below the updates*

Wednesday 8/10/16 Update]

It has now been two days since the Delta ground stop affected all their flight operations. The final number for Tuesday cancellations was 800. Though 15o cancelations have been accounted for today, normal operations are expected to resume this afternoon. Bill Lentsch, Delta’s Senior Vice President— Airport Customer Service and Airline Operations:

We’re in the final hours of bouncing back from the disruption. Delta employees have been working around the clock and are committed to bringing the airline back to full strength. We know this has been a rough couple of days for our customers and apologize to those who have experienced our less-than-stellar operation.

In addition, Chief Operating Officer Gil West addressed the cause of the technology failure:

Monday morning a critical power control module at our Technology Command Center malfunctioned, causing a surge to the transformer and a loss of power. The universal power was stabilized and power was restored quickly. But when this happened, critical systems and network equipment didn’t switch over to backups. Other systems did. And now we’re seeing instability in these systems.

[Tuesday 8/9/16 Update]

After yesterday’s power outage that grounded all non-departed Delta flights, the delays and cancellations have extended into today. The airline has cancelled 650 flights by Tuesday evening with delays expected as well. 2,400 flights had departed by Tuesday evening. For all affected travelers, the travel wavier set in place has been extended thru today so passengers can rebook for free.

The final cancellations for yesterday was around 1,000 flights.

Dave Holtz, Senior Vice President of Operations and Customer Center stated:

We were able to bring our systems back on line and resume flights within a few hours yesterday but we are still operating in recovery mode. We are sorry for what many of our customers have experienced over the past 24 hours, including those who remain at airports and continue waiting for their flights. We are doing everything we can to return our operation to normal reliability, but we do expect additional delays and cancellations.

[Monday 5:00pm ET] The most recent number from Delta is that 650 flights were canceled and many more where/are delayed:

[Main Story]

In the early morning of August 8, 2016, Delta had a major computer failure that stopped all flight not already in the air from departing. This caused massive delays throughout the entire Delta operation. Delta reported early in the morning that it was due to a power outage in Atlanta, where they are based:

A power outage in Atlanta, which began at approximately 2:30 a.m. ET, has impacted Delta computer systems and operations worldwide, resulting in flight delays. Large-scale cancellations are expected today.

It wasn’t till around 8am ET that the ground stop was lifted and limited departures began. Delays and cancellations will continue throughout the day and might even take a couple for Delta to fully get on track. Anyone that had Delta tickets on August 8, 2016 can rebook by August 12, 2016 because of the interruptions: http://www.delta.com/content/www/en_US/traveling-with-us/advisories/system-outage.html.

FlightRadar24 data really showed the difference between yesterday and today with the affected flights:

All @Delta flights not currently in the air are ground stopped due to a computer outage. https://t.co/2ifKusDe7b pic.twitter.com/pw0Z99MniN

— Flightradar24 (@flightradar24) August 8, 2016

We also looked at like how thin the Delta flights looked about an hour after the ground stop was lifted compared to United Airlines:

After #Delta ground stop, large scale cancellations in effect. Comparison of current Delta and United flights: pic.twitter.com/dwxOKxzfVS

— Fanda! Aviation (@FandaGear) August 8, 2016