Back up the press here.
Your computer was connected to the internet (your service is Spectrum) and the service crashed? i.e. you lost internet.
This shouldn't have hosed up your system. At best, any application which required internet connectivity would have stopped responding.
Hold the shift key down and click on the Apple icon on the top menu bar. Select Force Quit Finder.
Or hold the option key while clicking on the Finder icon in your dock. Select relaunch.
If Finder is still not responding. Shut down your machine. Let it sit there for a few minutes. Then restart it. This poor cycles the computer.
If it still doesn't function, click on the Launchpad icon on your dock. Find your Terminal app and open it.
Type the following line: rm ~/Library/Preferences/com.apple.finder.plist
Hit return. Then restart your computer. This removes any corrupted .plist files for Finder. Harmless as these are recreated at startup if missing. Hence the reboot.