Mark and Colin : Thanks a lot for all yours informations.
Actually, Germans (Head Quarter of the 15th german army) left quickly Tourcoing on the 2nd september and the résistants of the town "saved themself" Tourcoing. I don't remember when the allied troops entered in the town. Tomorow, I will try to watch again the film-pictures of the Liberation of Tourcoing and to meet civil witnesses.
Thank you again for this informations !
Cheers
Julien