On Sunday, May 21, 2000, at 1:30 p.m., the Bruce Grey Owen Sound Health Unit in Ontario, Canada, posted a notice to hospitals and physicians on their web site to make them aware of a boil water advisory and that a suspected agent in the increase of diarrheal cases was E. coli O157:H7.

There had been a marked increase in illness in the town of about 5,000 people, and many were already saying the water was suspect. But the first public announcement was also the Sunday of the Victoria Day long weekend and received scant media coverage.

It wasn’t until Monday evening that local television and radio began reporting illnesses, stating that at least 300 people in Walkerton were ill.

At 11:00 a.m., on Tuesday May 23, the Walkerton hospital jointly held a media conference with the health unit to inform the public of outbreak, make the public aware of the potential complications of the E. coli O157:H7 infection, and to tell the public to take the necessary precautions. This generated a print report in the local paper the next day, which was picked up by the national wire service Tuesday evening, and subsequently appeared in papers across Canada on May 24.

Ultimately, 2,300 people were sickened and seven died. All the gory details and mistakes and steps for improvement were outlined in the report of the Walkerton inquiry.