Six-year-old boy walks 2km to save mum after car ploughs into river bed

A six-year-old boy walked an incredible distance to get help after his mum's car crashed into the West Coast's Arahura River bed, north of Hokitika, on Friday night. 

The 41-year-old woman had been driving with her child when their car crashed.

She was unable to free herself as the vehicle was swept down the river. 

Her son, however, was able to escape and walk the two kilometres to State Highway 6 when a member of the public found him around 2am. 

Police launched a full-scale search and rescue before finding the woman on a beach several hours later seven kilometres north of the Arahura River. 

Sergeant Mark Kirwood, the officer in charge of West Coast Search and Rescue, said the woman is lucky to be alive. 

"It was established she had gone down the river and into the ocean before being washed ashore north of the river mouth," he said. 

"She is currently being treated for hypothermia in Greymouth Hospital."

Her son was unharmed and is in the care of relatives. 

West Coast Police offered their thanks to the large number of volunteers and partner agencies that assisted with the search for the woman. 

"We put the call out for assistance and it was answered en masse by LandSAR volunteers, Fire and Emergency NZ, Surf Life Saving New Zealand, the Coastguard and members of the jet boating community.

"We were also greatly assisted by the new Garden City Helicopter which had a search member on board with thermal imaging equipment."