French authorities have launched an investigation into the mysterious disappearance of a family of four near Nantes in Western France. Pascal and Brigitte Troadec, both about 50 and their children Sebastien, 21 and Charlotte, 18 have not been seen since Feb. 16. Officials say there has been no activity in their bank accounts and their phones have been off since Feb. 17 Prosecutor Pierre SennA s says bloodstains matching the DNA of three of the four family members have been found under the stairs, on Sebastien's cell phone and on Brigitte's watch.