Crisis over, but people in Walkerton still advised to boil water

The man who blew the whistle on the deadly E. coli outbreak in Walkerton, Ont. says the crisis is over.

Dr. Murray McQuigge says no new cases of E. coli infection have turned up in more than a month.

But he's still advising people there to boil their water.

An E. coli outbreak in the municipal water supply in May killed at least seven people, and made 2,000 others sick. It was the worst outbreak of its kind in Canadian history.

The province's clean water agency is now going door-to-door, disinfecting pipes.

And a team of 30 provincial police officers are in the town this weekend, interviewing people about what happened.

They're trying to find out how the water became tainted. They also want to know if proper procedures were followed once the contamination was discovered. Regional health authorities have said several days passed before any local officials notified them.