Yesterday, around 1,000 people missed flights from Dublin Airport after large queues formed outside both terminals. Thousands more were forced to wait in line for hours, before managing to catch their flights.
Airport operator daa has apologised to those who have missed flights and have said "out-of-pocket expenses" will be issued, but there are still many questions left unanswered.
Here is what we know so far:
Will I get any of my money back for my flight?
According to the Competition Consumer Protection Commission, travellers do not have an automatic right to redress from airlines if they do not make it to their flight departure gate on time, even where this was due to security delays within the airport.
However, the daa has confirmed that passengers who missed flights as a result of long queues can claim any out-of-pocket expenses they subsequently had to pay.
This will include costs incurred in changing flights, such as any overnight accommodation needed if flights were missed, and related taxi or other transport costs to and from hotels.
Affected passengers can make a claim by emailing firstname.lastname@example.org, with the daa hoping to have a claims form online soon.
People hoping to claim will have to have receipts and other proof of expenses in order to be reimbursed.
In a statement, Aer Lingus said it had waived change fees on flights departing on Sunday, to allow customers change travel plans, but added that a fare difference may apply.
The statement added that the delays "caused considerable disruption to the Aer Lingus schedule" and that the issues were outside of their control.
Ryanair CEO Eddie Wilson said that around 1,500 people missed flights on that airline alone yesterday, although no shows do account for some of that.
daa Chief Executive Dalton Philips will appear before the Oireachtas Committee on Transport on Wednesday to discuss the delays.
Further details of what compensation will be offered and how it will be processed is expected to be detailed then. Mr Philips is set to step down from his current role in September.
Are any of my other holiday expenses salvageable?
Many travellers will have had hotels, tourist attractions and other activities planned and paid for. Initial feedback from daa would make it seem that these expenses will not be covered, but it has been contacted for further comment.
Chairman of the Consumers Association of Ireland Michael Kilcoyne has advised those impacted to gather receipts and items of expenditure here and overseas that they had to make as a consequence of delays.
He said to take an account of days lost as part of the holiday and keep records as well as contact a solicitor.
I have travel insurance. Am I covered?
Purchasing travel insurance generally protects customers against the cost of emergency medical treatment abroad, personal liability, cancellation due to unforeseen illness, injury or death.
Due to this wide range of potential cover, policy terms and conditions vary between providers, according to Insurance Ireland, the representative body for insurance companies in Ireland.
"Travel insurance policies do not generally cover long queues at the airport," a statement from the organisation said.
However, some policies may cover travellers if they miss a flight due to airport delays. This may include cover for a refund of flights, the cost of rebooking a flight, or cover for a hotel stay, if required.
The Competition Consumer Protection Commission recommends that travellers check the policy terms and conditions for what cover, if any, they may have.
Insurance providers should be contacted as soon as possible for more information and if anything is unclear.
I'm travelling from Dublin Airport soon and I'm now worried. What should I do?
The existing advice from Dublin Airport is to arrive up to 2.5 hours before a short-haul flight and up to 3.5 hours before a long-haul flight.
People who are due to fly at or after 8.30am have been asked by daa not to arrive at the airport before 6am. They advise travellers to contact airlines directly to confirm check-in desk and bag drop opening times.
Many people travelling on Sunday reported incorrect security wait times on the Dublin Airport app. Daa has been asked for comment on this.
What caused these queues in the first place?
Daa is currently in the process of hiring around 700 people, with a spokesperson saying that more than 200 have been hired so far.
However, for people being recruited into the airport security unit and search unit, there is another six- to eight-week background check involved to allow them to get from airside to landside and vice versa.
SIPTU Industrial Organiser with the Aviation Sector, Jerry Brennan, said that too many people were let go at daa in the past few years and he did not think anyone suspected that aviation would come back and rebound as quickly as it did post-Covid.
Who is to blame?
The Government and daa have been taking the brunt of blame for the missed flights.
Speaking on RTÉ’s News at One, Mr Kilcoyne labelled the incident as a "pure disaster" and called on the Government to look at the daa Board.
He said he had "no confidence" in the board's ability to run a public airport and that passenger numbers should have been foreseen.
He also placed blame on the Government, saying that they have a responsibility to ensure consumers access to a public service airport.
Minister of State at the Department of Transport Hildegarde Naughton described a meeting with daa as "very frank and robust" adding that she was left "angry and frustrated" at scenes from Dublin Airport.
Fine Gael TD Kieran O'Donnell, who is Chairperson of the Joint Oireachtas Committee on Transport said he is embarrassed for Ireland following the chaotic scenes at the airport yesterday.
In a social media post yesterday, Dublin Airport apologised for the "obvious frustration and inconvenience" that was caused.
Will this happen again?
When Mr Philips appears before the committee on Wednesday, he will be expected to outline precisely how they will ensure that this will not happen again.
There are concerns that there may be similar scenes next weekend - which is the June Bank Holiday weekend - a typically busy time for the airport.
The daa has been told to report back by tomorrow morning on solutions that can be put in place ahead of the bank holiday weekend to deliver an "acceptable passenger experience".
Ryanair CEO Eddie Wilson has called for the army to be deployed to help to alleviate the lengthy queues at Dublin Airport. This request has already been quashed by Taoiseach Micheál Martin.