Severe thunderstorms in Atlanta caused a groundstop lasting five hours on Wednesday and set in motion a Delta meltdown from which the airline has yet to recover (on Sunday evening). Delta says it expects things to be back to normal by Monday (tomorrow). This article in the AJC explains how a day of storms on Wednesday turns into more than 3,300 cancelled flights by Sunday evening: http://www.ajc.com/travel/why-one-d...ve-day-delta-meltdown/6iwLZXfRcLKB0w1LAdKvpI/ One major failure has been Delta's overly optimistic predictions of when the recovery would occur - on Friday, Delta spokesholes said that by Saturday, things should be back to normal. You never want to over-promise and under-deliver; much better to communicate honestly and accurately with customers. This will be costly for DL, as the August computer meltdown last year cost Delta about $100 million in lost revenue: http://www.ajc.com/business/delta-outage-price-tag-100-million/2gewyWrTw0t7JObiAhcV3N/ The computer failure caused about 2,300 cancelled flights over four days, while these storms account for 1,000 more flight cancellations over about five days. Back of the envelope calculations lead to an estimate of about $125 million in lost revenue. As eolesen said when DL terminated the interline agreement with AA: DL cancelled its flood insurance because it hadn't seen a flood in a quite a while - now DL has suffered two major floods in eight months. Of course, AA could not have accommodated all the displaced DL passengers, but I have to wonder if new management (Bastian) will call Parker next week and see about a mutually beneficial interline agreement. Not having one is like denying an inexpensive spare part to a competitor - it may not bite you today, but eventually, you're gonna need a cheap spare part that only your competitor possesses at some outstation, and refusing to sell it to you is gonna cost you a bunch . . .