Awoman died and a man was left fighting for his life after a fatal crash in Somerset at the weekend.

Witnesses looked on in horror as flames engulfed a car which had veered off the carriageway and into a ditch.

The crash happened at about 4.30pm on Saturday on the M5 between Burnham-on-Sea and Weston-super-Mare.

A woman from the London area, thought to be in her 20s or 30s, was trapped in the Peugeot 206. She was declared dead at the scene.

But thanks to the efforts of an unknown hero, a man was freed from the same car and airlifted, by the Great Western Air Ambulance (GWAS), to Frenchay Hospital in Bristol, where he remains in a critical condition.

A spokesman for Great Western Ambulance said the car became trapped between a ditch and a fence before bursting into flames.

He said: "The female patient had already passed away but the male patient was rescued by a member of the public.

"Thanks to this brave member of the public, the patient was not injured by the fire."

Seconds later, an off-duty member of GWAS arrived on the scene.

Dan Merino, a dispatch assistant with the service, was travelling to Cornwall for a holiday when he spotted the accident.

Although GWAS had received several calls, Mr Merino, who normally works in one of the GWAS control rooms, rang through to his colleagues to give vital information about the scene to help crews on their way.

He said: "It was a terrible incident. Sadly, the female had already passed away. The male patient was unconscious and seriously ill.

"A brave member of the public was able to pull him from the car and save him from the fire. The member of public was helped by a number of off-duty medical staff. There were two A&E nurses and a consultant who were able to assist with vital live-saving skills."

Fred Thompson, a clinical team leader with GWAS, was on scene at the incident and said: "It was a great joint effort. The patient was suffering severe head and facial injuries. He was also suffering from severe chest injuries caused by the impact. With the aid of the doctors, the patient was anaesthetised and two chest drains were put in."

The southbound carriageway was closed following the crash, and two lanes on the northbound side were closed briefly, to allow the air ambulance to land.

Police re-opened the motorway at about 9.45pm on Saturday after conducting a full examination of the scene. They are now appealing for witnesses.

Anyone with information is asked to call Avon and Somerset Police on 0845 456 7000 or Crimestoppers on 0800 555 111.