Missing wp-includes folder

Hi,
I have built wordpress site but was changing some code on my “under construction” index.html on the home directory. I have now found that i can’t access my wordpress site which is hosted in the directory below:

https://www.rickybowry.com/site/

This is the error message:

Warning: require(/home/rickybow/public_html/site/wp-includes/load.php) [function.require]: failed to open stream: No such file or directory in /home/rickybow/public_html/site/wp-settings.php on line 19

Fatal error: require() [function.require]: Failed opening required ‘/home/rickybow/public_html/site/wp-includes/load.php’ (include_path=’.:/usr/lib/php:/usr/local/lib/php’) in /home/rickybow/public_html/site/wp-settings.php on line 19

I went into my FTP and the wp-includes folder is missing? Any idea where this went or how i can get it back?

Thanks.