CAIRO (Updated) - The Cairo Metro was Wednesday overcrowded with passengers for thefifth consecutive day after a fire in the el-Marg Station on Saturday. Waves of passengers (seen in this photo) are pushing each other to have a room inside the metro after half-an-hour wait. The system, crisscrossing the populous Egyptian capital, scoops more than 2 million a day off Cairo's busy streets. Meanwhile, prosecutors began investigations into the circumstances of the fire that erupted in a subway signal control room in northern Cairo on Saturday. Preliminary inspections revealed that the fire had originated in the low-voltage cables that supply the room's generators.