German discount supermarket chain Aldi says Theo Albrecht, its co-founder and considered one of the country's richest men, has died. He was 88. The company's Aldi Nord division said Wednesday that Albrecht died in his home city of Essen on Saturday. It didn't give a cause of death. Albrecht and his elder brother Karl went into the retail business after World War II and the first Aldi stores opened in the 1960s. Aldi now has more than 4,000 outlets in Germany alone and has stores across Europe and beyond. The publicity-shy Albrecht brothers have regularly led lists of Germany's richest people. 