A member of the Royal Australian Navy was killed when his motorcycle and a car collided in Secret Harbour yesterday.
The 50-year-old was driving north along Mandurah Road when he collided with a white Holden Commodore station wagon at the intersection with Surf Drive about 6.20am.
He died at the scene, taking the number of motorcyclists killed on WA's roads in the past 10 days to six.
Sgt Adrian Doulis said it appeared the 20-year-old driver of the Commodore had pulled out of Surf Drive in front of the motorcyclist.
He urged motorists to take care on the roads and be aware of driving conditions.
Parts of Surf Drive and Mandurah Road were closed while police interviewed witnesses and tried to piece together the crash scene.
Lance Kautai, who was driving about 20m behind the biker at the time of the crash, said the man did not have enough time to brake before he hit the car.
"It just happened so fast," he said. "The bike swerved off to the side and I had to dodge his body and the bike at the same time."
Mr Kautai left the scene a few minutes after the accident but returned a short time later when he heard the man had died.
"I found out that the fella had passed and I just felt bad, like I owed an explanation or something," he said. "I'm sorry that it happened. I called my partner after finding out he passed and I just told her I loved her."
A Department of Defence spokesman said the local navy command was providing the man's family with support.
The driver of the Commodore was not injured and is helping police with their investigation.
The horror run for motorcyclists started last week when two bikers died in as many days after hitting cars in Seville Grove and North Perth.