All 4,200 chickens on board a truck that caught fire on Adelaide's South Eastern Freeway have died in the blaze or will be euthanased.
About 30 fire crews worked to extinguish the blaze, which happened on the down track between Mount Barker and Hahndorf just before 4:30am.
About 900 chickens died in the initial blaze and another 1,100 were put down by the RSPCA at the scene.
The driver escaped unharmed.
In a statement, the RSPCA said said the rest of the chickens on board "suffered respiratory issues as a consequence of smoke inhalation".
"They have been transferred to a different vehicle and taken to the Cavan facility to be euthanased," the organisation said.
Fire cause investigators visited the scene.
"It [the fire]is believed to have started as a result of overheated bearings in one of the truck's wheels," the RSPCA said.
Both lanes of the freeway's citybound track were closed until 9:00am.
Car traffic was diverted through Hahndorf at Mount Barker, while trucks and buses continued to get through on the freeway.
Fires destroy sawmill and unit
Meanwhile, police are investigating a suspicious fire that destroyed a disused sawmill at Mount Gambier.
It happened on the corner of Radiata Street and Pick Avenue about 5:00pm yesterday.
Investigators say the fire was deliberately lit and that they will continue working to determine the cause of the fire.
It caused about $250,000 damage.
And a home was destroyed by fire in Elizabeth East with a damage bill of $150,000.
It is believed to have started in the lounge or kitchen of the property on Yorketown Road about 9:30pm.
Police evacuated the block as 20 firefighters worked to extinguish the blaze and save adjoining units.
Some sustained smoke damage but most residents were able to return.
