Thousands of passengers have been left stranded due to flight disruptions in the US, with multiple airlines, including American Airlines, Delta Air Lines, JetBlue, and Southwest, affected by grounded and delayed flights. However, there is uncertainty about the cause and scope of the disruptions, with some reports attributing it to airspace closures, while others mention a halt by the FAA or issues with specific airlines, including a reported shutdown of Spirit Airlines. Additionally, some reports suggest that the disruptions may not be limited to air travel, with cruise ship passengers also possibly being stranded in the Middle East.