BuddyPress.org

Try to rename wp-content/plugins/buddypress to something else and then access your site.

Is your sites front end accessible from http://www.website.com/main/. where you had it.

Is it wordpress/wpmu.

I guess, most probably, it should be an issue with the siteurl in the database. You might have given it to http://www.website.com/ at the time of installation, please check and provide more details.