German authorities said Tuesday that a 12-year-old boy was behind the most deadly blaze in Berlin's postwar history, after a fire killed nine residents of an apartment building occupied mainly by immigrants. The Berlin prosecutor's office said the boy had accidentally caused the devastating blaze, which was originally attributed to arson, when playing with pieces of paper and a lighter. After the flames began to spread, the boy and his nine-year-old brother attempted to alert tenants. But the stairwell of the five-storey building in the city's diverse Moabit district soon became engulfed in flames and smoke. Many of the foreign residents did not understand rescue workers' orders, delivered in German, to remain in their apartments and
attempted to flee. Nine tenants from Poland and Kosovo, including four children and a teenager, died of smoke inhalation The boy who started the fire survived.