DescendantRemoving fires immediately before the Instance/Parent|Parent of a descendant of the Instance changes such that the object is no longer a descendant of the Instance. Instance/Destroy|Destroy and Instance/Remove|Remove change an object’s Parent to nil, so calling these on a descendant of an object will therefore cause this event to fire.

Since this event fires before the the descendant’s removal, the Parent of the descendant will be unchanged, i.e., it will still be a descendant at the time of this event firing. If the descendant is also a child of the object, It will also fire before ChildRemoved. There is no similar event called “DescendantRemoved”.

If a descendant has children, this event fires with the descendant first followed by its descendants.

Example

The example below should help clarify how DescendantRemoving fires when there are several objects involved.

• Calling Instance/Remove|Remove on PartA would cause DescendantRemoving to fire on both ModelA and Model, in that order.
• Setting the Instance/Parent|Parent of PartA to ModelB would cause DescendantRemoving to fire on ModelA but not Model (as Model would still be an ancestor of PartA).
• Calling Instance/Destroy|Destroy on ModelA would cause DescendantRemoving to fire multiple times on several objects:
  1. On Model with ModelA, PartA then FireA.
  2. On ModelA, with PartA then FireA.
  3. On PartA with FireA.

Warning

This event fires with the descendant object that is being removed. Attempting to set the Instance/Parent|Parent of the descendant being removed to something else will fail with the following warning: “Something unexpectedly tried to set the parent of X to Y while trying to set the parent of X. Current parent is Z”, where X is the removing descendant, Y is the ignored parent setting, and Z is the original parent of X. Below is an example that demonstrates this:

workspace.DescendantRemoving:Connect(function(descendant)
	-- Don't manipulate the parent of descendant in this function!
	-- This event fires BECAUSE the parent of descendant was manipulated,
	-- and the change hasn't happened yet, i.e. this function fires before that happens.
	-- Therefore, it is problematic to change the parent like this:
	descendant.Parent = game
end)
local part = Instance.new("Part")
part.Parent = workspace
part.Parent = nil -- This triggers DescendantRemoving on Workspace:
--> Something unexpectedly tried to set the parent of Part to NULL while trying to set the parent of Part. Current parent is Workspace. 

See also Instance/DescendantAdded|DescendantAdded.