To delete multiple events online you should use the List View. This shows your events as a list. You can select the events to delete using the checkbox on the right, then choose Delete at the bottom of your list.
You can use the filter/search to only show specific events that match your criteria rather than all your events.
If the events you need to delete were created from a recurring/repeating event, then you can open any event in the repeating set, click the Flow tab, then choose 'View All' to automatically filter and show these events in the List view, where you can then choose which to delete.
Last updated on May 2, 2016