The community can try to help but more information is needed. Can you share a screenshot of your events?
And just to state the obvious, you want to use the Object->Destroy action to destroy objects.
EDIT: I see your second post now.
What is likely happening is that only the last instance is getting destroyed, as that is the instance currently picked. You should use a sub-event and add the condition "Pick All" -> cone. Then destroy. This should work