Which disappearance got the most media coverage?

There may not be one clear answer without defining “widest.” Are you counting coverage across countries, total news reports, or how long the story stayed in the news? Those measures could point to different cases.

I’d be careful about treating online search results as a complete ranking. Older coverage can be harder to find, and a large number of repeated reports is different from broad attention across regions. A useful comparison would need a time period, a set of media sources, and a clear counting method.