By Patrick White
MONTREAL, Aug 15 (Reuters) - Canada woke up on Friday morning as power was slowly being restored across Ontario and airline flights resumed in many parts of the country after one of the biggest blackouts in North American history.
But a state of emergency continued in Ontario where Premier Ernie Eves urged people to remain at home and save energy and asked them not to drive to conserve fuel. Businesses were also asked not to operate.
Canada's most populous province said it was generating only a fraction of the power it needs under normal circumstances.
For several hours, one in three Canadians had no electricity on Thursday as the blackout cut power to some 10 million people after the severe outage.
"Power is coming up in little bits," said a spokesman at the Ministry of Ontario Public Safety and Security. In the Canadian capital of Ottawa, the public utility said half of the city households had power early on Friday morning.
"Expectations are the power will be coming on throughout the day," the ministry spokesman told Reuters. "You can't have it all (come on) at the same time."
Bob Runciman, Ontario minister of Public Safety and Security, said the electricity system was still fragile.
"If we all continue to use electricity the way we would normally, the system is at risk of failing and causing more blackouts," Runciman said in a statement.
In Toronto, Canada's largest city, traffic was light and power was sporadic but the downtown area looked good, early morning travelers said.
The Toronto Transit Commission said it will operate a limited service until further notice. No subway or street car service will operate in Toronto, but buses were expected to run with some delays.
Case Ootes, deputy mayor of Toronto, said: "What we're most concerned about is to ensure that once the power is up that it stays up, that we don't get have recurring blackouts or brownouts."
Air Canada , the country's largest airline, said it resumed operations to and from Toronto, Ottawa and cities in the northeastern United States.
"While customers should expect flight delays and some cancellations throughout the airline's network as operations resume following the electrical outage, Air Canada expects to return to a full operating schedule by the end of the day," the Montreal-based company said.
Television showed long lineups of passengers waiting in at Montreal's Dorval Airport.
Via Rail, Canada's main rail passenger service, said trains will run on Friday in the key Windsor, Ontario-Quebec City corridor, as power returns to many locations.
On the business front, the Toronto Stock Exchange said it will open on time and for business as usual on Friday morning, despite the widespread power outage.
It has said no data from Thursday's session was lost due to the outage.
($1=$1.39 Canadian)