A suspected firebombing occurred on Stevens Street in Yarraville, west of Melbourne's CBD, at 2:30am when someone deliberately set two cars alight in a front yard, causing the fire to spread to a double-storey weatherboard house. A young family of four, including two adults and two children, safely evacuated and were checked by paramedics before staying with family and friends. Police detectives are investigating the incident as a deliberate arson attack.