Trying To Figure Out Why A System Locked Up And Hung

I had to bump a server we have over at the planet, but I cannot seem to determine the cause of its unresponsiveness (everything down to even simple ping). I checked APF logs and it didn't show anything except its normal periodic refresh of rules and such. I also see an selinux warning about proftpd trying to get to proftpd.conf and I saw something about selinux blocking mysql from using mysql.sock as well - I temporarily disabled SELINUX all together (it was in targeted mode). In the log files, it did log the fact though that it received SIGTERM and was going to runlevel 0, so it wasn't completely dead. I've gone through quite a few other logs and have come up empty handed. Is there anything else I can do? I want to get to the bottom of this.