apache won't start

[bluemerlin]

I switched from apache to nginx and back again and now apache won't start with the following error.
Starting httpd: /bin/bash: /usr/sbin/httpd.event: No such file or directory

I've rebooted, run /script/cleanup, /script/fixweb, /script/restart-web.

This is 6.5

[MRatWork]

Inform here 'yum list httpd* mod* nginx*'.