MADRID, SPAIN - MARCH 08: King Felipe VI of Spain and Queen Letizia of Spain (C) attend tribute concert 'In Memoriam' for terrorism victims at the Auditorio Nacional de Musica on March 8, 2017 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)
MADRID, SPAIN - MARCH 08: King Felipe VI of Spain and Queen Letizia of Spain (C) attend tribute concert 'In Memoriam' for terrorism victims at the Auditorio Nacional de Musica on March 8, 2017 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)