In 2007, a hospital porter was killed by a Weevil which had gone rogue in Cardiff and come up from the sewers. The Weevil was contained on a floor of the hospital by Torchwood Three with the cover story of a chemical leak to isolate the ward. Gwen Cooper, in an attempt to find out more about Torchwood, broke the seal and was followed by the porter. Believing the Weevil a man in a mask, the porter got close enough to have his throat ripped out.
Torchwood had covered his death by retroactively changing the work rotas for the day. They also established a false alibi that he was seen leaving the hospital. This gave him forty-eight hours before his body was pulled out of the docks the next Tuesday night, so he was "missing" for three days. (TV: Everything Changes)