P124 MTV3 p124 .To 24 Elo 1548:44 2/2 FIVE KILLED IN BLAST AT POSCO PLANT IN S.KOREA ... STATE RADIO SAID THE EXPLOSION WAS CAUSED BY A SMALL FLAME THAT IGNITED TRACES OF AMMONIA GAS AS WORKERS FROM A SUB-CONTRACTOR OF POSCO WERE TRYING TO CHANGE A GAS PIPE LEADING TO A FURNACE AT A COKE PRODUCTION FACILITY IN THE POHANG STEEL MILL. POSCO IS ONE OF THE WORLD'S LARGEST STEEL FIRMS. <123 125>