Network Theme Update Locked Site in WP Maintenace Mode

I just auto updated the Network theme to the latest update on my WPMS. Now my entire site is locked in the WP maintenance mode with the following message "Briefly unavailable for scheduled maintenance. Check back in a minute."

I've deleted the theme via ftp but this did not force WP to default to the default theme. I can't login again or do anything to get past this message.

Any suggestions?