Navigate to the Checklist Admin menu, and select Manage Live

From here, you can see all in-progress checklists at your selected location.

If you have access to multiple locations, use the drop-down menu to select the location you wish to view.

Click the orange Delete button to cancel the progress and delete the checklist. If the checklist was a retest, a new version will not appear.

Note that some checklists can only be deleted by authorised users.