The chief executive of Monarch said the airline's demise had left him "absolutely devastated", adding that disclosing the decision on Monday (2 October) made it a "heartbreaking day" as approximately 2,000 people lost their jobs.
Andrew Swaffield said the carrier's hierarchy decided to wind up operations late on Saturday night (30 September), after estimating that losses for next year would exceed the £100m (€113m) threshold.
Britain's fifth-largest airline ceased to operate with immediate effect in the early hours of Monday, after failing to secure a temporary extension to its Air Travel Organiser's Licence (ATOL) for the third time in four years.
This meant it was no longer able to sell ATOL-protected holidays and has since appointed KPMG as administrators.
Some 750,000 future bookings have been cancelled as a result, with around 110,000 Monarch customers stranded overseas.
Speaking to BBC Radio 4's Today programme, Swaffield admitted the carrier had been hit hard by terrorist attacks in Turkey and Egypt, which saw its rivals turn toward Spanish destinations, traditionally one of Monarch's strongholds.
"The root cause is terrorism and the closure of some markets like Turkey, Tunisia and Egypt," he said. "Flights were being squeezed into a smaller number of destinations and a 25% reduction in ticket prices on our routes created a massive economic challenge for our short-haul network."
Of the 2,000 Monarch employees who have lost their jobs, Swaffield said every effort was being made to find them new roles, adding the airline workforce had always felt like a "great family", which made the decision to cease operations even harder.
"We are doing all we can," he said. "We are talking to our competitor airlines, trying to organise job fairs and trying to connect staff with our competitors.
"We also have hundreds of head office staff in Luton and are trying to organise the same kind of conversations with employers in Luton and Bromley."
German low-cost carrier Air Berlin and Italy's flagship airline Alitalia filed for insolvency in August and April respectively but have continued to fly since. Swaffield, however, explained it would impossible for a British airline to follow a similar course of action and that once the decision to close the company had been taken, Monarch had no means to continue flying.
"The UK insolvency framework doesn't allow airlines to continue flying unlike in Germany and Italy, where we see that Air Berlin and Alitalia continued when they were in administration," he said.
"Here an airline can't keep operating for more than a day. We tried to operate a normal schedule all day Sunday so we could be ready for the Civil Aviation Authority (CAA) rescue flights on Monday morning without causing a massive backlog."
Meanwhile, 12,000 people have already been brought back to the UK on 61 flights chartered by the CAA in the largest peacetime repatriation operation in British history.
The aviation regulator estimated over 10,000 people are expected to fly back on Tuesday (3 October), adding the operation will run until 15 October and reiterating that Monarch customers would not have to cut their holidays short.
"Day one went really well and day two is going well so far but it is a huge undertaking and I'm sure there will be some glitches on the way," CAA chair Dame Deirdre Hutton told BBC Breakfast.