UPDATE: THE CFA's chief was unaware of predictions a Kilmore East bushfire could cut a devastating swathe through six other towns.

CFA chief officer Russell Rees told the bushfires royal commission he did not know an aircraft had made a line scan of the fire that was mapped in the Integrated Emergency Co-ordination Centre (IECC) in East Melbourne, the Herald Sun reports.

That showed the fire could sweep through Kinglake, Kinglake West, Strathewen, Pheasant Creek and St Andrews.

Earlier, he told the commission that adequate warnings were given to Kinglake residents caught in Black Saturday fires, as he stressed the CFA did not have a duty to warn people.

Meanwhile, terrifying new footage has surfaced of the bushfire roaring down on Kinglake (see right).

A woman can be heard saying residents were being evacuated as monster flames loom overhead.

Today, Mr Rees also said that warning sirens could be used to warn communities in the future.

 Mr Rees, who was based at the IECC, said he thought the fire had potential to be significant, based on information he was receiving from local control centres, fire spotters and from 000 calls from the public.

But he said it was a fire that was never under control at any point, he said.

Jack Rush QC, counsel assisting the commission, said the fire was reported at 11.49am on February 7 at its ignition point .

Fire prediction analysts had plotted the potential course of the front some hours before it reached the Kinglake area, he said.

The experts at the IECC had predicted at 1.14pm that the fire was heading to Kinglake.

Mr Rush said that it was possible to predict the seriousness of the threat to the Kinglake area given the fuel load, the fact the fire was into state forests and the potential for a south west wind change.

But Mr Rees said he had no knowledge of the mapping made the fire prediction analysts, although he now accepted it was largely accurate. 

The royal commission is undertaking a rigorous examination of the events and circumstances of Black Saturday that resulted in the deaths of 173 people and destruction of more than 2,000 homes and properties, AAP reports.

The royal commission started  today with a minute's silence.

The first person called to give evidence was Luke Corbett, operations planning officer for the CFA.

He was followed by Mr Rees.

Ewan Waller, the head of fire and emergency management at the Department of Sustainability and Environment, was to be next followed by Victoria Police Deputy Commissioner Kieran Walshe.

The chairman of the royal commission, Bernard Teague, said there would be a rigorous examination of the events and circumstances of Black Saturday that resulted in the deaths of 173 people and destruction of more than 2000 homes and properties.

Justice Teague said the first block of hearings would focus on what happened on February 7, particularly the warnings and aspects of the stay or go policy.

"The commission will examine individual fires including timing, intensity and the impact of wind and the south-westerly change on the fires,'' he said.

"Our primary focus will be on issues that will help create a safer environment for Victorian communities.

"We will concentrate on how to limit the devastation of any future intense bushfires and save lives.''

The hearings is being held at the Victorian County Court in Melbourne and streamed live on the internet.

In a submission to the royal commission, a community fireguard group blames a communication breakdown for the "terrible losses'' on Black Saturday, as people were overrun by fires they didn't know were coming.

The 100 Acres Community Fireguard group, based at Park Orchards on Melbourne's eastern fringe, says bushfires should be graded according to their intensity and howling sirens activated to warn residents in their path.

It also proposes mandatory battery-operated radios for residents in fire prone areas and wants all media to broadcast fire threat messages.

Other submissions have also criticised the warning system and blame poor management of fuel loads and vegetation for contributing to the February 7 catastrophe that killed 173 people and destroyed more than 2000 homes.

Submissions close on May 18 and are gradually being uploaded to the royal commission website.

The royal commission will hand down an interim report on the Black Saturday fires by August 17.

A final report is due by July 2010.