People on this forum have reported purposely closing their FB accounts, on their own or in response to requests from SO's, or, overreacting to SO's objections to specific use of FB. They have also reported that their SO's have purposely closing FB.

Nobody has ever reported an accidental deletion of a FB account, either by themselves or by their SO's.

FWIW...

I am afraid to do so myself for fear of pressing a wrong button, but you should try deleting your FB account, counting how many steps it would take, but without pressing the last button. I bet you will know by the end of that exercise...