Deleted activities

How can we find out who or how deleted events scheduled on the calendar? I received a notice this morning, because I have the setting on my Google calendar, that someone has deleted activities for two different groups in Primary. I want to be able to contact the person or those who made the mistake because it is kind of odd to have both of them disappear at the same time.

There is no way to know. You can look at who had editor rights to that calendar, including the unit leaders (Bishopric, Executive Secretary, and clerks).