I'm using PHP5, CodeIgniter and Apache. The localhost php pages were loading fine and then suddenly they started crashing Apache.
The web pages seem to get to different stages of loading when apache crashes.
The only interesting line in the Apache error log file says :
[notice] Parent: child process exited with status 3221225477 — Restarting.
There is a lot of discussion of this issue on the web but it seems there is no one solution, different people have described different solutions that worked for their system.