I was in a group of 9 people and we started with some icebreakers and casual chatting. Then went on to do 1 on 1 interviews, again very casual and more of a chat than an interview.

Large group interview with info on the company and the role itself. Then team tasks for ice breakers and then split into individual interviews. This was a new site opening however so not sure if this would be the same if you were starting at a site that was already open.