site just went down, only thing done was update a handful of plugins

a new site I'm working on (fortunately still under development) won't load... i.e. a blank screen is all that I get:

all I've done:

- I updated the following plugins (basically those that saw updates in July), only by uploading the files, hadn't opened wp-admin yet:

ad sharing, admin ads, admin footer text, avatars, friends, mailchimp, recent global comments, comment indexer, remove email verification, supporter

- I updated .htaccess for the avatars plugin (& then reverted it, no dice).

any ideas of what I can look into to get this site active again? I'm at a loss here.