After a recent Bitbucket connection issue resulting from [this|https://bitbucket.status.atlassian.com/incidents/l50d1j43zdj9] Bitbucket outage, the [Bitbucket brance source plugin|https://wiki.jenkins.io/display/JENKINS/Bitbucket+Branch+Source+Plugin|https://wiki.jenkins.io/display/JENKINS/Bitbucket+Branch+Source+Plugin] deleted all our projects. Once the plugin was able to connect to Bitbucket again, all previous builds were deleted and the build numbers restarted from 1.