There is no information out-of-band
Just a few minutes after I posted that, there was a blog post and Twitter status update -- so LocalBitcoins did address the outage out-of-band eventually.
As far as what happened:
LocalBitcoins received a very dangerous attack against the site infrastructure
The site will be down for a while as the system is being rebuilt
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http://localbitcoins.blogspot.com/2014/05/attack-against-localbitcoins.html