Second death, dozens of firefighters injured as bushfires wreak havoc in SA

More than a dozen homes have also been lost in the treacherous fire conditions across South Australia.

A house burns in the Adelaide Hills. Source: AAP

A person has been killed in a bushfire in the Adelaide Hills and at least 15 homes have been destroyed as fires rage across South Australia.

On Saturday morning, Premier Steven Marshall voiced his concern that the initial damage could be "only the tip of the iceberg."

A Woodside resident battles a fire on Friday. Source: AAP

"We know that in addition to the buildings and vehicles lost there are very significant losses in terms of livestock, animals, crops, vineyards," he said.

"It is going to be a real scene of devastation, especially for those people in the Adelaide Hills who have been most affected."

South Australian Country Fire Service chief Mark Jones said 23 firefighters had been injured - with one member seriously hurt and still in hospital.

"Against the catastrophic conditions and the backdrop of unprecedented challenge, it is remarkable so few of the firefighters and emergency responders were injured," Mr Jones said.

Three Country Fire Service trucks were also destroyed.

On Friday, authorities confirmed another person had died when their car slammed into a tree near the scene of a blaze at Lameroo.

Firefighters in the Adelaide Hills on Friday. Source: AAP

The ABC is reporting that former Oakbank Racing Club chairman John Glatz was among those injured in the fires.

Police have confirmed they are currently checking on the welfare of up to 100 people across the various fire grounds.

On Friday's day of catastrophic conditions, more than 100 fires broke out before midday and have since destroyed about 40,000 hectares.

The remaining fires of most concern are the blaze in the Adelaide Hills and another blaze burning along the north coast of Kangaroo Island.

Both are uncontrolled with fire crews and water bombers working to protect assets and establish control lines.

They believe both fires will continue to burn for several days.

Watch and act warnings remain in place, however Mr Jones said there is always the potential for those to be upgraded to emergency level - should conditions deteriorate or the fire activity escalate.