Sounds like Windows, so if you can start Task Manager and kill InDesign or restart the computer. If you can't do that, hold down the power button to shut of the laptop. With luck, when you reboot and restart ID auto-recovery will kick in and you won't have lost much, at which point you should follow the instructions at Remove minor corruption by exporting.
If auto-recovery fails, you'll need to find your InDesign Recovery folder and empty it. It's a hidden folder (you can show hidden folders and files in windows explorer using Folder Options > View tab, and by default it will be in C:\Users\<USER>\AppData\Local\Adobe\InDesign\<Version #>\<Language>\Caches\. This should let you start ID normally and you can open the last saved version of your file using File > Open... unless that has also become corrupt, in which case you're probably out of luck.