Dear developers! Please, consider adding a mechanism which upon a trigger deletion would immediately schedule all events which were created by this trigger to be deleted by the "housekeeper" without having to wait for the time period set in the 

"Administration">"General">"Housekeeping">"Events and alerts">"Trigger data storage period"

As these events are not visible in the GUI, but are still present in the DB.

And usually when such "orphaned" event entries are found the suggested workaround from us is to:

SET SESSION SQL_LOG_BIN=0;
DELETE FROM events WHERE source = 0 AND object = 0 AND objectid NOT IN (SELECT triggerid FROM triggers);