How to terminate a zombie instance.

Hi.

I deleted the fleet, but there are instances left.

Region is Tokyo and c4.large instance

If you try list-fleets via the AWS CLI, there are four fleets running as shown in the image below

8312-list-fleets.png

However, with describe-fleet-capacity, it seems that the deleted fleet has an instance like the image below

So there are actually 2 instances in use, but there are 17 instances in service limit page

Is there a way to delete a zombie instance?