Police were called to the Riddoch Highway, near the town of Nangwarry, near the Victorian border, following a three-car pileup around 2.40pm yesterday.

A black Holden sedan hit an emu, causing a gray Toyota to brake suddenly and crash into the rear of a white Nissan ute, police said.

The five-year-old boy, a passenger in the Toyota, died instantly.

Another passenger, a 15-year-old girl, was taken to hospital in critical condition.

The driver of the Toyota, 42, and three other passengers in the car aged 46, 13 and 6, were taken to hospital with minor injuries.

The driver of the Nissan, 22, from Worrolong, was uninjured.

The woman whose car hit the emu was also not injured.

Police from the Major Crash Unit are currently investigating the scene.

The young boy’s death marks the 71st life lost on South Australia’s roads this year.