You can delete event
To delete an alert:
Click the Alerts tab, if it is not already displayed.
Click to the right of the alert you want
to delete.
A pop-up window prompts you to confirm the deletion.
Click Yes to complete the deletion.
You return to the Alerts tab, and the deleted alert is no longer listed. When you delete the last alert of a certain type (such as an event alert), the section for that type of alert no longer appears on the Alerts tab.