South Australia detectives began investigating a suspected fire at Marino Conservation Park last night.
Just before 11pm on Thursday paramedics were called to a park near Bundarra Drive following reports of a fire.
It took firefighters for hours to extinguish the blaze, which threatened infrastructure and nearby homes.
At one point the nearby Seaford railway station had to be closed for safety.
The cause of the fire is unknown but officials have reason to believe it may have been deliberately set on fire.