Using the latest stable, 1.20.1 I believe. No mods.
I don't think it was lightning as there wasn't a storm at the time. I had just planted a bunch of pumpkin seeds that I had found in a jar before going to bed, so I know that the crops were still there at that time. I had woken up, walked outside and got smacked by the bear as it came around my house. From that point it was a lot of running around, me dying, and re-spawning about 50 blocks away. I went to go check on my pit kiln when I noticed that everything was gone. Also, I was placing the soil in double rows of 10 with a space of water in between each double row, and the shore is slate gravel, so if a fire had started on one it wouldn't have been able to jump the others.
I checked the Archived logs folder and I'm able to find the timestamp where I killed the bear in the client audit logs. However the server audit logs start after that time, like the game over-wrote them.