Wikipedia:Articles for deletion/Disappearance of Sarah MacDiarmid
While I was previously unfamiliar with this case myself, the sources Jenks24 has provided certainly establish it as notable.  http://newsstore.fairfax.com.au/apps/viewDocument.ac;jsessionid=E48A3686E1E7B0333AD1AFB274F4009C?page=1&sy=age&kw=Sarah+MacDiarmid&pb=all_ffx&dt=selectRange&dr=entire&so=relevance&sf=text&sf=headline&rc=10&rm=200&sp=0&clsPage=1&docID=AGE100710IC8US3DB5KP This news article, for instance (just one of many), suggests that it's still very much in the national consciousness twenty years after the fact, and seems to speak to the criteria in  about duration of coverage, as well as implying that it did "have a significant impact over a wide region"&mdash;it seems to have been covered in national papers, and I'd consider all of Australia a sufficiently wide region to qualify
— User:Smeazel, 08:05, 26 May 2011 (UTC)
Stance: keep
Cited policy: WP:EVENT (Wikipedia:Notability)