Grounded XL planes at Manchester airport
The collapse of XL Leisure Group has disrupted the plans of 67,000 holiday-makers already abroad, and has meant the cancellation of 200,000 advance holiday bookings.
The company, one of the UK's biggest tour operators, blamed its insolvency on "funding and cash flow issues".
In other words, it has run out of cash.
The Civil Aviation Authority (CAA), using its ATOL scheme, has swung into operation to make sure everyone abroad gets home with as little disruption as possible.
But not all customers are in the same position.
What if I'm stuck abroad?
People on package holidays abroad who booked through the XL group's UK businesses, including those who booked a flight with its Freedom Flights operation, will be flown home at no extra cost by the CAA once it has made the arrangements.
If you booked a package tour or flight with another tour company which had planned to use an XL flight then that operator will also make alternative arrangements for you.
Get in contact with them directly.
Your holiday should not be cut short if you are abroad.
The CAA says it will make sure that hotels and staff in resorts will be paid so that holiday-makers abroad can continue to enjoy themselves as normal.
An estimated 10,000 people who bought flight tickets on an XL plane either through the website www.xl.com or through a travel agent and are currently abroad are not formally covered by the ATOL scheme.
But the CAA says it will arrange to bring you home anyway, though you will be charged the cost price of the flight.
If you do not like that idea, you can make your own arrangements, at your own cost.
I have not flown abroad yet - what about me?
Do not go to the airport. Your holiday has been cancelled.
If you booked an XL holiday, or a flight with Freedom Flights, you will get your money back by claiming a refund from ATOL.
Your travel agent should help you do this.
Those who had advance bookings for flights only with XL Airways will not get compensation from ATOL.
Can I claim on my credit or debit card?
If your flight is not covered by the ATOL arrangements you are advised to try to get your money back by contacting your credit card company (if you paid by credit card).
Under the law, if you spent £100 or more on your tickets you can claim a full refund from the credit card company - Visa or Mastercard.
If you paid by a Visa debit card then your bank may be willing to try to get your money back from XL's bank.
But it is not clear whether this will happen in this case, even if your own bank is happy to have a go.
XL is now in administration and any money still in its bank accounts is under the jurisdiction of the administrators.
Will my insurance policy help?
Because the holiday industry has the ATOL scheme, and because holiday company and airline failures may be huge, most holiday or travel insurance policies exclude them from cover.
There may be a few policies that do not though, says the Association of British Insurers (ABI), so it is worth checking your small print.
What about my Medlife Hotels booking?
This was an accommodation agency run by XL.
Those Medlife customers already abroad may be able to complete their holidays, XL said.
But they are not covered by ATOL either.
Customers with advance bookings will also have to seek a refund from their credit card companies or banks.
They could also check their travel insurance to see if it covers "accommodation failure".
But again, if the reason for the failure was the collapse of a tour operator or an airline, then that may invalidate such cover.
Am I now a creditor of XL?
Overall, anyone who has lost money and is not bailed out by the ATOL scheme, or who incurs extra expenditure as a result of XL going bust, has become a creditor of the firm.
You should contact the administrators, Kroll Ltd, but in reality you are unlikely to get much money back, if any.
Where can I get more information?
The CAA says your first port of call if you have any further questions should be the ATOL website: www.atol.org.uk.
It will be regularly updated as more information becomes available on new arrangements for inbound flights.
If you are abroad and need urgent help, call the CAA emergency helpline: +44 (0) 2891 856 547
If you are a UK customer with an advance booking with a tour operator, call the CAA helpline: 0870 5900927
Customers who booked with the XL call centre or the XL website and who want to claim money back should contact the administrators Kroll.
Kroll's helpline is 0800 068 8991 is calling from the UK and +44 (0) 208 242 4783 for customers abroad.
Alternatively you can send details of your claim to: Kroll Limited, Wellington Plaza, 31 Wellington Street, Leeds. LS1 4DL.