Is there a way to discover why my server had a high load

Just now I was forced to remotely reboot my CentOS 6.3 system due to a ultra high load (75!) that paralyzed the system. This is a web/mail server that serves a wordpress blog (mySQL + PHP). Is there any log I can analyze and try to discover what cause that? This is the email I have received now from the system about the event yesterday: This is an automated message notifying you that the 5 minute load average on your system is 75.91. This has exceeded the 10 threshold. One Minute - 83.24 Five Minutes - 75.91 Fifteen Minutes - 39.35 top - 22:25:30 up 122 days, 7:28, 0 users, load average: 99.14, 80.70, 42.31 Tasks: 298 total, 1 running, 297 sleeping, 0 stopped, 0 zombie Cpu(s): 1.2%us, 0.5%sy, 0.0%ni, 98.1%id, 0.3%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1020176k total, 956828k used, 63348k free, 2788k buffers Swap: 4194296k total, 1391900k used, 2802396k free, 25164k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1 root 20 0 19352 448 444 S 0.0 0.0 0:08.27 /sbin/init 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kthreadd] 3 root RT 0 0 0 0 S 0.0 0.0 0:09.43 [migration/0] 4 root 20 0 0 0 0 S 0.0 0.0 1884:48 [ksoftirqd/0] 5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 [migration/0] 6 root RT 0 0 0 0 S 0.0 0.0 0:06.06 [watchdog/0] 7 root RT 0 0 0 0 S 0.0 0.0 0:07.81 [migration/1] 8 root RT 0 0 0 0 S 0.0 0.0 0:00.00 [migration/1] 9 root 20 0 0 0 0 S 0.0 0.0 7:25.62 [ksoftirqd/1] 10 root RT 0 0 0 0 S 0.0 0.0 0:04.58 [watchdog/1] 11 root 20 0 0 0 0 S 0.0 0.0 4:48.95 [events/0] 12 root 20 0 0 0 0 S 0.0 0.0 9:13.85 [events/1] 13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [cgroup] 14 root 20 0 0 0 0 S 0.0 0.0 0:08.21 [khelper] 15 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [netns] 16 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [async/mgr] 17 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [pm] 18 root 20 0 0 0 0 S 0.0 0.0 0:21.72 [sync_supers] 19 root 20 0 0 0 0 S 0.0 0.0 0:20.65 [bdi-default] 20 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kintegrityd/0] 21 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kintegrityd/1] 22 root 20 0 0 0 0 S 0.0 0.0 5:26.09 [kblockd/0] 23 root 20 0 0 0 0 S 0.0 0.0 0:22.90 [kblockd/1] I am not sure if this can help. Everything appears to be using 0% of CPU.. this is another email.. This is an automated message notifying you that the 5 minute load average on your system is 70.53. This has exceeded the 10 threshold. One Minute - 94.79 Five Minutes - 70.53 Fifteen Minutes - 32.68 top - 22:23:34 up 122 days, 7:26, 0 users, load average: 96.88, 74.74, 35.91 Tasks: 283 total, 2 running, 281 sleeping, 0 stopped, 0 zombie Cpu(s): 1.2%us, 0.5%sy, 0.0%ni, 98.1%id, 0.3%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1020176k total, 970440k used, 49736k free, 3196k buffers Swap: 4194296k total, 1249404k used, 2944892k free, 29836k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 6715 apache 20 0 217m 7804 3252 D 1.9 0.8 0:00.28 /usr/sbin/httpd -k start -DSSL 6770 apache 20 0 218m 8772 3368 D 1.9 0.9 0:00.28 /usr/sbin/httpd -k start -DSSL 6799 apache 20 0 301m 8088 3184 D 1.9 0.8 0:00.14 /usr/sbin/httpd -k start -DSSL 7265 root 20 0 15160 1220 808 R 1.9 0.1 0:00.02 /usr/bin/top -c -b -n 1 7266 root 20 0 15160 1220 808 R 1.9 0.1 0:00.02 /usr/bin/top -c -b -n 1 1 root 20 0 19352 448 444 S 0.0 0.0 0:08.27 /sbin/init 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [kthreadd] 3 root RT 0 0 0 0 S 0.0 0.0 0:09.43 [migration/0] 4 root 20 0 0 0 0 S 0.0 0.0 1884:48 [ksoftirqd/0] 5 root RT 0 0 0 0 S 0.0 0.0 0:00.00 [migration/0] 6 root RT 0 0 0 0 S 0.0 0.0 0:06.06 [watchdog/0] 7 root RT 0 0 0 0 S 0.0 0.0 0:07.81 [migration/1] 8 root RT 0 0 0 0 S 0.0 0.0 0:00.00 [migration/1] 9 root 20 0 0 0 0 S 0.0 0.0 7:22.58 [ksoftirqd/1] 10 root RT 0 0 0 0 S 0.0 0.0 0:04.58 [watchdog/1] 11 root 20 0 0 0 0 S 0.0 0.0 4:48.95 [events/0] 12 root 20 0 0 0 0 S 0.0 0.0 9:13.85 [events/1] 13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [cgroup] 14 root 20 0 0 0 0 S 0.0 0.0 0:08.21 [khelper] 15 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [netns] 16 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [async/mgr] 17 root 20 0 0 0 0 S 0.0 0.0 0:00.00 [pm] 18 root 20 0 0 0 0 S 0.0 0.0 0:21.72 [sync_supers] Yes, I am using Apache. 75 is the load average saw on top for the last 5 minutes.