From the Internet

English Idiom: in case of

Origins in the legal phrasing "The case of..." (legal cases are usually negative events)

As an idiom used to denote a contingency the "the" is replaced by "in".

As a rule plans are made for good outcomes and contingencies are made only for the bad.

Internet High Authority
(scroll down to post # 6)

Last edited by themilum; 08/04/2007 9:36 PM.