Two people died after an explosion and a fire at a biodiesel plant in La Rioja in northern Spain early on Thursday afternoon. The factory and the whole El Recuenco industrial zone in Calahorra were evacuated immediately after the accident, according to El Día de La Rioja newspaper and other media reports, citing the safety authorities. Some 250 children who were out on a school trip were also brought to safety. Videos made nearby and shared in social media showed a dense cloud of black smoke and flames after the blast that occurred at 1 pm (1100 GMT). All of the police and firefighting units a…