Stupid game. I get notified Sanctuary was under attack. I dropped what I was doing at another settlement and rushed back. I killed the Gunners who were attacking. I waited a little bit and no more appeared. I left to return to the other settlement I was working on and then I get a message saying I failed to protect Sanctuary. I return and find all of my generators broken, some of my water pumps and turrets broken. WTF?

Because someone at Bethesda had the great idea that when you invest your time in building settlements and putting good defences then you should not get attacked. Hence i only have been attacked 2 times in a 60+ hours playtrhough and in settlements that i havent built anything on them.

Yeah, I was aware of this fact. I mostly built the walls for aesthetic reasons - to make it look like a fortress. Same reason I have perimeter turrets and spotlights.

It hasn't happened to me (yet), but there is a thread around where someone completely fenced in Sanctuary, only to have enemies spawn inside.

There's lots of conflicting information out there right now, about what causes settlement attacks (or prevents them from happening). I've also read today that, once you hit level 50, your settlements will start getting more frequently hit by raiders in power armor, and heavily armed super mutants.

Sanctuary has over 100 in defense. That place is lined with turrets. There shouldn't be any failure from attack.

That happened while I was there. I have it walled up with two entrances. Bastards.

My Sanctuary has been attacked about four times so far. I've managed to defend it each time. Unfortunately, I was browsing the settlement list just yesterday looking for issues and noticed that Sanctuary was listed with zero food, water, etc. I decided it was a bug and fast-traveled back home just to check... I was wrong. Everything needed repair. I was floored. I have defenses and turrets set up everywhere. The defense rating is somewhere in the mid-300's. I figured that it would take an army of Behemoths armed with Fat Man to take it down.

I started backtracking my game saves trying to figure out what had happened. A few minutes into the past and everything would appear fine in Sanctuary, but while examining it in build-mode each resource would slowly dip to zero as if whatever had happened was slowly catching up. I finally found a game save where Sanctuary was being attacked... by three radscorpions coming down the path from Vault 111.

There wasn't even a legendary among them, and I mopped them up fairly easily. However, I could see how they might wipe out my settlement when they would quickly burrow underground and pop up elsewhere. All my defenses expect a frontal attack, and if the enemy can burrow past them or hide while under fire then they're pretty useless.

I've also noticed a disturbing trend where the attackers somehow manage to appear right in the middle of the settlement or if I don't respond quickly enough to a call to arms then the settlement will just be wiped out. I thought at first that my defenses were simply inadequate, but if the default game behavior requires the player to be present when a settlement is under attack in order for it to be saved, then I have to wonder why I'm spending time and resources building up settlement defenses when I have to be half-way across the map on a mission.