NANCY, France -- Investigators trying to determine the cause of a train fire that killed 12 people, including five Americans, reconstructed the scene of the blaze Friday.

The German train attendant was part of the two-hour simulation in the eastern city of Nancy, as was a train car identical to the one destroyed.

Prosecutor Michel Senthille said the agent was not where he was supposed to be when the fire broke out early Wednesday on an overnight train from Paris to Munich, filling a sleeping car with smoke.

"He was supposed to be in the car where the fire started, but he wasn't there. He was trying to get back," Senthille said.

The German car had no smoke detectors, though cigarette smoking was allowed. Germany's national railroad said it was considering introducing smoke alarms on sleeping cars, now not a requirement in Europe.

Five Americans, three German men, two Russians, a Hungarian man, and a Greek woman were killed.

The Americans killed were from the same family. Salvatore Michael Amore and his wife Jeanne, both 43; their children Emily Jeanne, 12, and Michael Bernhardt, 8; and Salvatore's 72-year-old mother, Susanne. They were all of North Branford, Conn.