At least three construction workers died when a traffic tunnel collapsed in the small south-western European country of Andorra Saturday, Spanish radio broadcaster RNE reported, , according to dpa. Search efforts are underway in the rubble for one more missing worker. Seven, all suffering serious injuries, have already been rescued. Work was underway on the three-kilometre long tunnel to connect the communities of Encamp and La Massana in the principality in the Pyrenees mountains. The unexplained collapse happened during the installation of a cement ceiling.