Can't remove site collection with powershell command

Hello,

I tried running this PowerShell command:

Remove-SPSite -Identity "http://devspfam/sites/chinook" -GradualDelete

Confirm
Are you sure you want to perform this action?
Performing operation "Remove-SPSite" on Target "http://devspfam/sites/chinook".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help
(default is "Y"):y

But PowerShell says it cannot complete this action. Please try again. In Central Admin, the site collection appears in the site collection list, but when selected Central Admin does not show the URL, Title, Description, Administrator, Email Address and database name.

How can I remove this orphaned site collection?

Thanks.

Paul