An express train barreling through a seaside station in northeastern Spain plowed into youths cutting across the tracks to get to a midnight beach party, killing at least 12 people, injuring 14 and turning a night of celebration into one of carnage and tragedy. It was Spain's deadliest train accident since 2003.A large group of people _ many of them Latin American immigrants _ got off a commuter train in the beach resort of Castelldefels south of Barcelona shortly before midnight Wednesday to head to the party. As the crowd jammed an underpass heading to the beach, about 30 people climbed down off the platform and tried to scurry across the tracks instead, witnesses said. Seconds later, a long-distance train that does not stop at the station crashed into the youths at high speed, its whistle shrieking. Marcelo Cardona, who was on the commuter train, said everyone on board had been looking forward to dancing around a bonfire on the Mediterranean shore. “The euphoria of getting off the train immediately became screams. There were people screaming, ‘My daughter! My sister!”' said Cardona, a 34-year-old Bolivian. He said he saw “mutilated people, blood everywhere, blood on the platform.” As an investigation got under way Thursday, the chairman of the state railway company RENFE, Teofilo Serrano, said he was “almost certain” the long-distance train was not exceeding the speed limit as it traveled through the station. He said he did not know how fast it was going. The Spanish news agency Europa Press quoted unnamed RENFE officials as saying the train was doing 139 km per hour and the driver tested negative for alcohol and was in shock. RENFE refused to confirm or deny the report. Felipe Elmaji, a 29-year-old Moroccan traveling with Cardona, said he heard a “thump, thump of the train hitting people.” Cardona's sister Candy recalled the shrill, piercing sound of the train's whistle as it tried to warn people to get out of the way. “It was horrible. I can't get that sound out of my head,” she said. Cardona said the underpass was jammed with the overflowing crowd from the train. Mayor Joan Sau blamed recklessness for the deaths. “If the underpass had been used, we would probably not be talking about this tragedy right now,” she said. Catalan regional Interior Minister Joan Saura said the identification of the mutilated bodies “will not be easy and it will not be fast.” Except for one woman in her 40s, all of the injured were 19 or younger and two are minors, said Marta Joves, spokeswoman for the Catalonia government's civil protection department.