And the Chilean miners trapped for a couple of months back in 2010? The fact that all I need to do to remind you of the event is mention 'Chilean miners' should be sufficient evidence to prove an exception to your proposed rule.
It was a lot of people (more than 30), and IMO wasn't covered as heavily as say, the Thai cave or this may be.
There is definitely a disaster angle news latch onto, but it's pretty rare for a group of adults this small. There are small plane crashes with more fatalities multiple times a year...
And it can't be the 'missing people' angle, there are like 400k kids every year reported missing with less than milk carton coverage...
The urgency tickles our savior complex. The situation makes us feel that we might be able to save those souls if only we could figure out the correct bash one-liner to solve it, and that grabs our collective attention.