Given the URL, error and speed of the crash, I'm guessing you're running WordPress on Apache+MySQL. There's no reason that stack can't handle HN-level traffic for a blog (especially at 3AM Pacific).

Activate a caching plugin WordPress to remove the database bottleneck.

Lower the MaxSpareServers/ServerLimit/MaxClients variables so that Apache can never start more processes than your system has RAM. Turn off KeepAlive or set the timeout very low so that those few processes you can handle running aren't tied up on people that have already loaded the post.

That should prevent the kind of crash that just happened.