A fire Saturday in a mattress factory in Casablanca, Morocco's economic hub, killed 55 people and injured a dozen others, the official news agency quoted local authorities as saying. A statement by the Wilaya of Greater Casablanca, the city government, said 55 people were killed in the morning fire and 12 injured. The MAP news agency had earlier reported 25 deaths. About 100 firefighters rushed to the scene in an industrial sector of Casablanca. The blaze began on the ground floor of the factory at about 10 a.m. (1000 GMT) and quickly spread through the five-story building, MAP reported. The official statement cited the presence of chemical products in the factory as responsible for the fire's rapid spread. However, the exact cause was not immediately known.