People who died in a Black Saturday bushfire that struck without warning should not have been relying on fire authorities or police to alert them to danger, a court has heard.

State entities say they had no legal responsibility to warn people of the Kilmore East blaze, the Victorian Supreme Court heard on Thursday.

The Country Fire Authority (CFA) gave general warnings to at-risk communities every bushfire season, telling them they needed to have bushfire plans in place and decide for themselves when to enact them, said the state's lawyer Chris Caleo SC.

"The recommendation that's made in the bushfire survival plan is if you know it's a high fire-risk day and you have already made your decision that you are going to be a person who leaves, then the declaration of a high fire-risk day might be your trigger to leave," he said.

"What people are told is, you don't wait until your area is threatened at all, that is too late."

Plaintiff Carol Matthews is leading a class action of more than 10,000 members suing the CFA, Victoria Police and the Department of Sustainability and Environment (DSE) over their failure to warn people of the blaze on February 7, 2009.

She is also suing SPI Electricity, alleging its negligence in failing to maintain power lines sparked the blaze.

All defendants deny the allegations and are fighting the claims, but SPI also has a cross-claim against the state entities.

Mrs Matthew's son, Sam, was one of 119 people killed in the blaze.

He had been constantly monitoring the CFA website, but there was never any mention that his home in St Andrews was under threat.

The court has heard that St Andrews was never mentioned in any warning by the state entities, even though authorities knew hours before that the fire was out of control and which communities stood in its path.

Fourteen people died at St Andrews.

Mr Caleo said the Kilmore blaze was driven by spot fires, which broke out up to 20 kilometres ahead of the fire front.

The CFA consistently told people at community meetings that they could not rely on authorities to warn them because of the unpredictability of spot fires, sparked by embers, he said.

He said a CFA script used by presenters at the meetings instructed people they could not expect warnings.

Mr Caleo said communities were told: "Fires may impact quickly before there is time to organise a warning."

"Experience has shown you cannot expect that `someone' (say police or fire brigade) will give you a personal warning," a public booklet tendered to the court said.