At least 55 people died and a dozen others were injured after a fire broke out Saturday in a mattress factory in Casablanca, the official news agency reported. The morning blaze began on the ground floor of the factory and quickly spread through the five-story building, theMAP news agency reported. About 100 firefighters rushed to the factory in an industrial section of Casablanca and battled the blaze for about three hours. The Wilaya of Greater Casablanca, the city government, said in a statement that 55 people died and 12 were injured, MAP reported. The government statement said chemical products in the factory caused the fire to spread rapidly, the agency reported. But the exact cause of the fire was not immediately known. advertisement Officials from the prosecutor's office opened an investigation into the fire, MAP said. The bustling coastal city of Casablanca is Morocco's leading port and the economic capital of this North African country. It reflects the contrasts of Morocco, the westernmost Muslim country, with its rich modernity and poor, crowded neighborhoods with soaring unemployment. Credit: CNN/AP