Day 3: 4:00 A.M.-5:00 A.M. - S3-E16
Corrected entry: Michelle and her staff sealed the hotel to keep the virus inside. But when the angry guest smashes the door to get out (so Michelle has to shoot him) no-one acts to seal the broken door. (00:59:00)
Correction: Viruses are very fragile and the reason the hotel was contained was not to keep the virus itself in but to keep all the guests in. They seal it off camera, though, to keep the guests from trying to escape that way.
SexyIrishLeprechaun