Removing "Lingering" Events in Calendar

Hi!

Some of my users have noticed events that have been cancelled still appearing on their calendars.

These events show up on their calendars, whether its in Outlook or on their Smart Phone. They're also in OWA.

The problem is that, sometimes people will try to delete them from their calendar and then it notifies all the participants, which sometimes is our entire staff team.

Is there a better way to help remove these events?

We're using Exchange 2010 with Office 2007 or 2013.

Thanks!

-Eric