(ANSA) – Carbonia, January 8 – A contract worker from the troubled Alcoa aluminium smelter in Portovesme, Sardinia, threatened to throw himself off a 20-m tower on Tuesday amid concern over social welfare provisions for laid-off workers. The incident took place at the ex Serbariu mine in the depressed Sulcis area where Alcoa workers had gathered to call for reassurances from national and local government concerning their social security situation. The emergency services intervened at the scene and managed to persuade the worker to climb down from the tower. He was subsequently taken to hospital for medical treatment. The latest protest follows last year's decision by the US aluminium giant to power down its Portovesme smelter, which employed hundreds of people in the area. The plant has technically been at a standstill since November 1, while Alcoa promised to keep all workers employed through the end of 2012.