The four-year-old was rushed to hospital after a two-car collision.

A young girl critically injured in a crash that closed a busy stretch of road has died.

The girl, aged four, was rushed to Fiona Stanley Hospital from the intersection of Boardman Rd and Garden St in Thornlie, a suburb in Perth’s south-east, about 3.15pm on Wednesday.

Tragically, she could not be saved.

The afternoon collision involved two cars — a grey Holden Astra travelling east on Boardman Rd and an orange Ford Mustang heading north on Garden St.

The young girl and an eight-year-old boy had been a passenger in the Astra, which was being driven by a 32-year-old woman.

The driver and boy were hurt in the crash, but their injuries are not life threatening.

The Mustang driver, a 29-year-old woman, suffered minor injuries.

The serious incident closed Garden St northbound between Forest Lakes Dr and Figtree Dr, and motorists were asked to avoid the area.

Anyone with information about the crash should contact Crime Stoppers.

A young girl has died in a crash in Thornlie.A young girl has died in a crash in Thornlie. Credit: 7NEWS

The tragedy came as a schoolgirl fights for life in Royal Perth Hospital after she was struck by a car in Malaga, in Perth’s northern suburbs.

The 15-year-old had stepped off a bus and was crossing Beach Rd about 5.20pm on Tuesday when she was hit, in front of her friends and shocked onlookers.

Bystanders rushed to help until paramedics arrived and she could be taken to Royal Perth.

One witness said he was pulling into a nearby gym when he heard a “big bang”.

“It’s a pretty scary situation seeing that right in front of you,” witness James told 7NEWS.

Police are investigating and no charges have been laid.

SOURCE: https://7news.com.au/news/five-year-old-girl-critically-injured-in-thornlie-crash-c-22380550