In July 1942, shortly after he was put on a train to Auschwitz, Zoltan Roth, a Romanian-born doctor living in France, threw a hastily written note on to the rails hoping that whoever found it would help save his children.
"Dear Madeleine, I beg you to look for the children," began the letter picked up by an unknown railway worker and sent on to the two friends to whom it was addressed.
"Give them a kiss for us, try to find whatever you need at home. If you need money for the children, sell the car."
Jammed into an airless cattle wagon, Roth and his fellow prisoners could do no more for those they left behind.
But more than 60 years after the Holocaust, some families and surviving deportees are suing the French government and the national railway operator SNCF for collaborating with France's Nazi German occupiers and sending thousands to their deaths.
Roth was among the few who survived. But when he came back, his wife Eda was dead and he learned that despite his friends' efforts, his children Michel, four and Liliane, 18 months, had spent their last months alone in a French transit camp before being put on a train for Auschwitz.
"Just thinking about these little kids alone, 18 months, four years, no one to turn to, haunts me," said Elisabeth Benfey, their half sister, born after the war when Roth remarried.
Now living in the United States, she has joined hundreds of others taking legal action after a landmark decision last year opened the way for victims of the Nazi deportations to sue French authorities for compensation.
"I feel very ambivalent about accepting anything that has to do with something so ugly, but I just find that the hypocrisy of it all has to be exposed," she told Reuters.
France has no US-style class action suits but around 100 applications are being filed against the French Ministry of the Interior and the SNCF this week. More are expected, despite the prospect of protracted legal wrangling.
The case is the latest episode in a painful process of coming to terms with the past triggered by President Jacques Chirac's acknowledgement in 1995 that France had "committed the irreparable" in deporting 76,000 Jews to Nazi death camps.
"I will never forget the atmosphere in that train, mothers crying, people screaming in pain, and the stench," said Alfred Knoller, who was sent from Paris to Auschwitz with 100 others in a wagon made for 40 men or 8 horses. Four died on the way.
"We had two aluminium buckets, one for drinking, one for sanitary purposes and people had to go in front of everybody," he told Reuters by telephone.
"After three days, the buckets were overflowing and the stench of excrement and urine was really a terrible thing."
Under a decree passed after the liberation of France in 1944, the new French government declared it was not liable for the actions of the collaborationist Vichy regime, a principle that was not overturned until 2001.
The SNCF, which said it had no option but to obey the orders of the German occupiers, has appealed against last year's ruling on the first action against it. But it was not until that case, launched in 2001, that further suits became feasible.
The action has nonetheless been criticised by some historians and Jewish groups who say it is misguided and opportunist, and there have been suggestions the families and the lawyers are motivated by financial considerations.
Henry Rousso, one of France's leading historians of the Occupation, told La Croix newspaper it was "grotesque" to equate a French railway worker with an "accomplice to Auschwitz".
It is an argument which cuts little ice with the families, who point to evidence that the SNCF charged French authorities the price of a third-class railway ticket for each person loaded into its cattle wagons.
"It is about money but not in the way they mean," said William Wajnryb, whose father died at Auschwitz.
"When people make accusations about money, they should look at the SNCF first of all," he said. "The core of this story is that the SNCF got money for deporting Jews."
Like others in the case, Wajnryb made a distinction between the SNCF as an organisation, and individual railway workers such as the one who helped get Roth's letter to its destination or countless others who played a heroic role in the resistance.
A study commissioned by the SNCF itself found that while the railway operator was quite willing to protest vigorously to the Germans about excessive demands in other areas, it was ready to pack thousands of Jews and others off to eastern Europe in plainly inhuman conditions without any apparent qualms.
There was no sign of "any refusal, any protest on the part of the transporter about how the transports were to be carried out," wrote Christian Bachelier, the historian who prepared the study, 'The SNCF under the German Occupation'.
Apart from belated compensation, the action's supporters also believe it serves a wider purpose.
Alain Lipietz, a European parliament member whose father Georges opened the way to the action by suing the French government and the SNCF in 2001, believes that the judgement delivered last year underlined the point that some crimes can never be erased.
"Making a criminal understand that they will never, never, never be exempt either as an institution or an individual, that they will always be answerable to the victim is one of the great victories of international law," he told Reuters.