message left on the home answering machine of employee Philip Bye. Bye, however, did not recognize the significance of E. coli being present in Walkerton water and, believing the measures public health officials had already taken to be sufficient to deal with the contamination, he did not pass the news on to the emergency response arm of the MOE that day. In the face of rising community casualties—by the evening of May 21, 270 people had contacted the Walkerton hospital after experiencing gastroenteritis symptoms, and one patient had had to be airlifted to London, Ontario, for treatment—the situation was being perceived as increasingly serious by most of those involved. That evening, the BGOSHU contacted the Minister of Health and the Chief Medical Officer of Health of Ontario. Requests were placed with the Ministry of Health for an epidemiologist and for staff to assist in treating Walkerton-region gastroenteritis patients; public health staff began looking into acquiring equipment that would be needed to treat any E. coli patients whose infections progressed to Hemolytic-Uremic Syndrome (HUS). David Patterson ordered further testing of Walkerton's water, sending James Schmidt to collect samples of water from various sources in Walkerton, including "food premises, hospitals, and the health unit office". Patterson received Schmidt's collected samples and drove them to London overnight. The samples were received by the London Regional Public Health Laboratory at 12:45 a.m. on May 22; a further round of sampling was ordered to be done the next day. Events of May 22 Despite increased awareness of the severity of the outbreak, as May 22 began, some links in the public safety chain were still uninformed as to either the existence of the outbreak or the fact that it presented a real and present danger to public health. Mayor David Thompson, himself suffering from symptoms of gastroenteritis, which he assumed to be flu, took no investigatory or emergency-preparedness action on May 22, nor did James Kieffer, chair of the Walkerton Public Utilities Commission (PUC), who had been alerted to the outbreak the day before. Ministry of the Environment (MOE) employee Philip Bye, who had been notified by Bruce-Grey-Owen-Sound Health Unit (BGOSHU) phone call the previous evening, did not understand that E. coli contamination was a life-threatening emergency; he took no action until he was contacted again later on May 22 by a concerned Dr. McQuigge. At that point, Bye sent an environmental officer to join