I had apache fail but it auto started back ok, error logs have this:
It did this three times but everything looks ok and is running fine. Top shows nothing out of the ordinary. I did get a load of traffic today, just wonder if it is a php issue.

[Fri Oct 15 12:33:14 2004] [notice] caught SIGTERM, shutting down
[Fri Oct 15 12:33:17 2004] [notice-phpa] Removed existing cache sems (pid 20281)
[Fri Oct 15 12:33:17 2004] [notice-phpa] Removed existing cache shm (pid 20281)
[Fri Oct 15 12:33:17 2004] [notice-phpa] Acquiring cache : uid 99 gid 99 perms 666 (pid 20281)
[Fri Oct 15 12:33:17 2004] [notice-phpa] PHPA 1.3.3r2 on linux_i686_glibc2.1.3 (pid 20281)
[Fri Oct 15 12:33:17 2004] [notice-phpa] Initialised 32MB cache at 0xb4ce5000 with 512 process entries (pid 20281)
[Fri Oct 15 12:33:17 2004] [notice-phpa] Lock thresholds 10/10 (pid 20281)
[Fri Oct 15 12:33:17 2004] [warn] NameVirtualHost 99.99.0.99:80 has no VirtualHosts
[Fri Oct 15 12:33:17 2004] [warn] NameVirtualHost 99.99.0.99:80 has no VirtualHosts
[Fri Oct 15 12:33:17 2004] [notice] Apache configured -- resuming normal operations
[Fri Oct 15 12:33:17 2004] [notice] suEXEC mechanism enabled (wrapper: /usr/local/apache/bin/suexec)

They only major change I made a while back was cpanel PRO.

what you where running before the shutdown?

can you post some before log?

/home/mercyhospit/public_html/404.shtml
[Fri Oct 15 12:32:15 2004] [error] [client 125.254.192.88] File does not exist: /home/mercyhospit/public_html/003/care1/graphics/background.jpg
[Fri Oct 15 12:32:15 2004] [error] [client 121.254.192.88] File does not exist: /home/mercyhospit/public_html/404.shtml
[Fri Oct 15 12:33:10 2004] [error] [client 121.156.89.88] File does not exist: /home/mercyhospit/public_html/002/care1/graphics/background.jpg
[Fri Oct 15 12:33:10 2004] [error] [client 121.156.89.88] File does not exist: /home/mercyhospit/public_html/404.shtml

There was also some FTP going on and this right at the time:

ACK URGP=0
Oct 15 12:33:14 svr1 kernel: ** OUT_TCP DROP ** IN= OUT=eth0 SRC=99.15.99.99 DST=209.89.99.149 LEN=1500 TOS=0x00 PREC=0x00 TTL=64 ID=65082 DF PROTO=TCP SPT=80 DPT=44689 WINDOW=6432 RES=0x00
ACK URGP=0

The last time we had problems, it was due to PHPA, try something else for a day to see if it resolves the error.