apache not starting - CentOS 6

The server went down but now that it's back up apache won't start. The OS is CentOS 6. Nothing has changed since yesterday when it was working fine so I have no idea why it is not working now. This is the error: Starting httpd: [Thu Jan 26 17:15:27 2012] [crit] (22)Invalid argument: alloc_listener: failed to get a socket for (null) Syntax error on line 136 of /etc/httpd/conf/[login to view URL]: Listen setup failed [FAILED]