Four people, including a child, have been involved in a serious car crash near Byford.
Thomas Road has been closed in both directions between Master Road and Plaistowe Boulevard while emergency services work.
Emergency services at the site.Credit: Main Roads WA
Two teenagers, an adult and a child are believed to have been involved,
Seven St John Ambulance are at the scene, along with the RAC helicopter and special ops teams.
Crews have taken a male teenager from the scene as priority one to Fiona Stanley Hospital.
Main Roads WA have warned motorists to expect delays from the closure and said drivers should exercise extreme caution in the area.
