diff --git a/changelog/snippets/fix.6629.md b/changelog/snippets/fix.6629.md
new file mode 100644
index 0000000000..8e9b929f38
--- /dev/null
+++ b/changelog/snippets/fix.6629.md
@@ -0,0 +1 @@
+- (#6629) Fix a rare error that would cause the Fatboy to not finish dying.
diff --git a/units/UEL0401/UEL0401_script.lua b/units/UEL0401/UEL0401_script.lua
index 58156e03b9..f1e756a1bc 100644
--- a/units/UEL0401/UEL0401_script.lua
+++ b/units/UEL0401/UEL0401_script.lua
@@ -17,6 +17,8 @@ local EffectUtil = import("/lua/effectutilities.lua")
 local ExternalFactoryComponent = import("/lua/defaultcomponents.lua").ExternalFactoryComponent
 local DefaultExplosions = import("/lua/defaultexplosions.lua")
 
+local IsDestroyed = IsDestroyed
+
 ---@class UEL0401 : TMobileFactoryUnit, ExternalFactoryComponent
 ---@field UnitBeingBuilt Unit | nil
 ---@field AttachmentSliderManip moho.SlideManipulator
@@ -258,7 +260,8 @@ UEL0401 = ClassUnit(TMobileFactoryUnit, ExternalFactoryComponent) {
         local explosionBones = {}
         local explosionBoneCount = table.getn(self.ExplosionBones)
 
-        if instigator then
+        -- Since this is a thread, it is delayed by 1 tick so the instigator may be destroyed
+        if not IsDestroyed(instigator) then
             -- if there is an instigator, favor exploding bits that are near the instigator
             local ix, iy, iz = instigator:GetPositionXYZ()
             for k, bone in self.ExplosionBones do