Team Foundation Server Work Items: How to delete a workitem created by mistake.

using tfs powertools:

C:\Program Files\Microsoft Team Foundation Server 2008 Power Tools>tfpt.exe destroywi /server:http://MyServer:8080 /workitemid:888

This action is not recoverable. Are you sure you want to destroy work item(s) 123? (Y/N)y

Operation complete.

for other reference regarding deletion kindly go to this site.