A baby has died and three others have been seriously injured after a Toyota Kluger left the road and slammed into a tree in Perth’s southeast.

The silver SUV was travelling along Nicholson Rd in Lynwood about 3.40am on Saturday when it veered off the carriageway and struck a tree, triggering a major emergency response.

A 35‑year‑old man — a ride‑share driver — was behind the wheel and sustained minor injuries.

The passengers, a 32‑year‑old woman and a seven‑month‑old child were rushed to Fiona Stanley Hospital with serious injuries.

But the baby later died despite efforts to save them.

A three‑year‑old child was taken to Perth Children’s Hospital, also with serious injuries.

Major Crash investigators are examining what caused the vehicle to leave the road and are appealing for witnesses.

Police are urging anyone who saw the crash, or the silver Toyota Kluger travelling in the area beforehand, to contact police.