This tweet is the nearest thing to a statement that I could find. It suggests their trading engine's database is corrupt, and there has already been a complaint from one of their customers that his balance is not correct. I've not found a proper official statement anywhere yet, only that tweet.
https://twitter.com/bitfinex/status/636258874606133248Bitfinex.com @bitfinex 2h 2 hours ago
We are experiencing data corruption issues and will be offline until corrected. Sorry for the inconvenience.