occur vs set off

occur and set off both are verbs.

Word	Noun	Adjective	Verb	Adverb
occur	No	No	Yes	No
set off	No	No	Yes	No

occur (verb)	set off (verb)
come to pass	cause to burst with a violent release of energy
come to one's mind; suggest itself	set in motion or cause to begin
to be found to exist	direct attention to, as if by means of contrast
	provoke or stir up
	put in motion or move to act
	depart for someplace
	make up for