Buses, streetcars and subways shut down at midnight despite assurances from the Amalgamated Transit Union 48 hours notice would be given, the Toronto Sun reported. Local President Bob Kinnear told reporters the decision was made for workers' safety after a last weekend's strike threat.

"We have assessed the situation and decided that we will not expose our members to the dangers of assaults from angry irrational members of the public," Kinnear said.

Mayor David Miller held a news conference at midnight and was clearly angry, the Sun said.

"This strike is unnecessary, unacceptable and irresponsible," he said, referring to a tentative agreement giving 9,000 workers a 3 percent pay hike in each year of the three-year deal struck last weekend.

The Toronto Star said Miller contacted provincial Premier Dalton McGuinty to request emergency back-to-work legislation.