By CARLOS BARRAGÁN About half an hour after Fernando Seco’s train left Madrid on Wednesday morning, taking him home to Seville, Spain, after a business trip, it stopped for a few minutes. A voice on the loudspeaker said there was heavy traffic. The train then started to move again — and after a while, Seco said, there was a “very violent crash.” He would soon learn that his train, run by Renfe, Spain’s national rail provider, had rear-ended another one, leaving dozens of people dead. Seco,…
