My most important site on my network (network is at has disappeared!!!

My multisite network (network root domain: appears to have lost one of my sites. I suspect a database issue. The site is siteid=11 and is with domain mapped as the primary domain for the site. The content is still in the site uploads folder on the AWS server instance. However, WPMU is throwing a site not found error. Other sites on the network are fine although the overall network is slow compared to my other WPMU network on another AWS instance. I appreciate the help!