Lerissa will bang on the exterior wall while calling to the others. "Are you guys OK in there?". She notes the exterior dimension of the building so she might be better able to place where she heard them last.
Feeling a bit more at ease by the sound of Mustapha's voice but still troubled by their not answering her banging on the side of the building and calling to them, Lerissa will repeat her call. "Are you guys OK in there?"