A rare nationwide ground stop caused chaos at Honolulu's airport and across the country, stranding passengers, cancelling flights, and leaving airlines scrambling to recover.

• All U.S. flights were grounded at once, only the third time this has happened since 9/11.
• Honolulu passengers sat on planes for hours, some flights were cancelled, and at least one plane got diverted mid-route.
• Jets ended up in the wrong cities and crews started timing out, so delays kept piling up well after the stop was lifted.
• Passengers said confusion spread fast, with many learning what was happening from their phones before airline staff said anything.

Outlook: Expect delays and cancellations to keep rippling through the next few days as airlines reposition planes and crews back to where they're supposed to be.