The wild weather appears to have contributed to two major incidents with one man in a critical condition when struck by a tree and a potentially serious crash on the South Eastern freeway.

The man is in critical but stable condition in hospital after a tree fell on him as he was helping SES crews clear a fallen tree on Nokia Drive, Ironbank overnight. 

The local storm that passed through the hills area at that time, also created icy conditions on the South Eastern Freeway. 

As two police patrols were returning from the Ironbank assignment, they came across a car that had spun-out near the Stirling overpass. 

As they assisted, an approaching semi-trailer lost control on the slippery road, crashing into a B-Double semi with both trucks then crashing into one of the parked police cars and narrowly missing the other. 

Both police officers were forced to take evasive action. One truck driver has been taken to hospital for treatment of his minor injuries.