If you've purchased your flight via credit card, you might be able to claim your money back through your credit card company. Most credit card companies will refund you any purchase that is between $100USD–$30,000 USD. However, it's important to note that different countries have different rules.
In the UK, it's much easier to claim money back off your credit company if an airline goes bust, as people in the UK are protected by Section 75 of the UK Consumer Credit Act. You'll first need to try and contact the airline or travel company that you booked with to see if there's anything that they can do. If you can't get an answer because the company has gone into liquidation, you'll then have to write to your credit card company, requesting a refund under Section 75 of the UK Consumer Credit Act.
In the US, it's fairly similar. Although the US law under Section 170 of the Fair Credit Billing act doesn't force credit card companies to protect and refund purchases, in almost all cases, credit card companies will refund flight purchases if the airline has gone bust.