At least 15 people are dead and 50 injured after a train derailed in northern Italy causing gas tanks to explode and destroy nearby homes. The accident occurred in the town of Viareggio when one carriage derailed, pulling another four with it, at around midnight. Liquefied petroleum gas escaped and caught fire, resulting in an explosion which shook people from their beds near the local station. News agency ANSA said two buildings had collapsed. Fire crews battled the blaze overnight in the Tuscan seaside town and emptied gas from other, unexploded tanks as more victims were searched for among the rubble. About 1,000 people were evacuated just after the blast. Television pictures showed the fire spreading down city streets, setting cars and nearby buildings alight. Rescue workers provided first aid to burn victims along the roadside. At least two children are among the dead - a grandfather screamed "let me see him! let me see him!" as a young boy's body was found. There are 37 people injured, either seriously or very seriously, rescue workers said. They include a two-year-old who was badly burned and transferred to a hospital in Florence. It is Italy's most deadly rail accident since 17 people were killed in January 2005, when a passenger train collided with a freight train near the northern city of Bologna.