The Lancastria sinking: A secret disaster

Fewer than half of those onboard the Lancastria survived.

The evacuation of British troops from France in 1940 did not end with Dunkirk.

British forces were still being rescued two weeks later when Britain's worst maritime disaster of World War II took place.

On 17 June, 1940 the British troopship Lancastria was sunk off the Brittany port of Saint-Nazaire. More than 3,000 people lost their lives.

The Lancastria, a converted liner, was carrying an estimated 6,000 people.

Bombs below the waterline ruptured the boat's fuel tanks

The Cunard ship was carrying RAF personnel as well as civilians, and some estimate there could have been up to 9,000 people aboard who had already just been rescued from the beaches of Dunkirk, along the French coast.

The ship sustained a direct hit, when a bomb landed down a funnel. The ship sank within minutes of being struck, killing over half of those on board.

At the time news of the disaster was suppressed by the British Government because of the impact it might have on the country's morale.

It was not until nearly six weeks later, on July 26, 1940, that the world discovered what had happened. The New York Times broke the story, printing some of the dramatic pictures of the disaster.

Those who escapeed were engulfed by huge quantities of leaking fuel oil

Some of the survivors, including Dorothy Cox's father, survived by clinging to debris from the ship in the oily waters off France.

She told us: "He never got over the experience and had nightmares for the remainder of his life, which sadly was short. He could never forget the men and women clinging to the hull of the ship singing patriotic songs as it sunk below the waves, and the young airman who jumped overboard and was cut to pieces by the propellers.

Covered in oil, many were loaded onto ships bound for the UK

"Dad was rescued by a fishing boat and taken to Dover, along with other survivors. From there he hastily wrote a message to my mother on a cigarette packet and threw it from the train window. Some kind passerby picked it up and posted it. It read 'I'm OK'."

Young crewman Frank Clements saw the sinking of the Lancastria from onboard the navy destroyer, the Highlander. As a keen amateur photographer, his pictures tell the tragic story of the Lancastria and are the only photographs of the stricken vessel's final moments.