Police are trying to determine whether two cars were drag racing before one crashed into a tree, leaving a teenage driver in a critical condition this afternoon.
The man’s silver car left Alexander Drive in wet conditions at 12.39pm and slammed sideways into a tree.
Onlookers rushed to the man’s aid before he was taken to Royal Perth Hospital, where he remains with critical injuries this afternoon.
Witnesses said the car had been heard revving its engine with a red car shortly before the crash.
Police have seized both cars and the male driver of the red car has been arrested as part of an ongoing investigation into the crash.
Sergeant John Smith said police believed the silver car was speeding but were still trying to determine whether the cars were racing.
He said the cars were not believed to have come into contact before the crash.
“We haven’t determined the speed at this stage but you can surely see from the impact on that vehicle, speed is definitely an issue here,” Sgt Smith said.
University student Cherie Barron, who witnessed the crash, said both cars appeared to be travelling above the speed limit.
“We looked up to see a silver car ahead of a red car coming towards us accelerating way too fast…they passed us, got to about 20m in front of us, the silver car moved into the middle of the road to stop the red car from passing him," she said.
“It’s just lucky none of us were on the road otherwise we would have been gone I reckon.”
Ms Barron said the silver car fishtailed before it mounted the kerb and hit the tree tree.
Ms Barron, a volunteer firefighter, was among a group of students and an off-duty nurse who gave first aid to the man before paramedics arrived.
“I think it happened in slow motion, it was straight into the tree, wrapped around the tree," she said.
"If there was anyone in the passenger seat they’d be gone straight away.
"We were just lucky we could get him out.”
The male driver is being interviewed by police this afternoon.
Sgt Smith said the uninjured driver was “concerned” for the other driver.
Police have asked for anyone who was at a bus stop near the crash site on Alexander Drive and saw the cars to contact Crime Stoppers on 1800 333 000.