Event, happening (8)
I believe the answer is:
incident
I believe this clue is a double definition.
'event' is the first definition.
(incident is a kind of event)
'happening' is the second definition.
(an incident is a happening or event)
(Other definitions for incident that I've seen before include "Confrontation" , "Falling" , "Episode" , "Happening (often of a criminal nature)" , "is liable to occur" .)