A 19-year-old Coogee man died after his motorcycle struck a sign in Beeliar on Saturday.
At about 6.30pm the man was travelling on East Churchill Avenue, where he mounted a kerb on a cul-de-sac.
A Major Crash spokesman said police believed the man came off his bike in an attempt to avoid a chain link fence.
“It was a single strand of wire that would’ve struck him in the head or throat,” he said.
“He put the bike down, but it appears he collided with a sign.”
Police suspect the man suffered internal injuries when he struck the sign, which was believed to be above a gas meter.
Saint John Ambulance took the man to Fremantle Hospital but he died shortly after arriving.