[CentOS] System Rebooted by 2.6.18-8.1.8.el5

Hello,

I have a machine that seemed to reboot by itself yesterday, in
/var/log/messages I only see:

Mar 25 14:26:45 asterisk shutdown[19256]: shutting down for system reboot

When I type: last reboot

I see:

  reboot   system boot  2.6.18-8.1.8.el5 Tue Mar 25 14:28          (18:41)

So it seems like the kernel rebooted, but I'm not sure how I can track
down why, any pointers?

Thanks!


Andrew