Man dies in SA freeway crash

A man has died after crashing his car into a tree east of Adelaide.

Police say he was treated at the scene on the South-Eastern Freeway in Monarto South about 3.30pm on Thursday but died a short time later.

Drivers have been warned to expect delays around the crash site for several hours.

The death takes South Australia's holiday season road toll to two.

* The national road toll period runs from 0001 December 23, 2015 to 2359 January 3, 2016 local times.