What was found
HEARD LOUD POP FOLLOWED BY EICAS BLEED 1 LEAK MESSAGE, LAVATORY SMOKE MESSAGE, BAGGAGE SMOKE MESSAGE, DISCHARGED BAGGAGE EXTINGUISHER - CABIN/FLIGHT DECK FILLED WITH SMOKE. EMERGENCY DECLARED AND RETURNED TO ORD. POST INSPECTION FOUND BLEED DUCT DISCONNECTED AND DAMAGE TO THE INSULATION UNDER CABIN FLOOR. REMOVED AND REPLACED DUCT, BLANKETS AND O-RINGS IAW EMB AMM. OPERATIONAL CHECK GOOD. RETURNED AIRCRAFT TO SERVICE.