At least 55 people were injured on Friday after a fire tore through an auto parts factory in Daejeon, South Korea, officials said, as emergency crews raced to locate more than a dozen people believed to have been trapped inside. The fire broke out around 1:00 p.m. (0400 GMT) and spread rapidly through the facility, sending thick gray smoke billowing into the sky. Its cause was not immediately known, said Nam Deuk-woo, fire chief of Daedeok District, though witnesses reported an explosion. Images from the scene showed workers leaping from upper floors to escape the flames. Fourteen people believed to have been inside the factory had not yet been located, Nam said. Police were tracking mobile phone signals to find them. Firefighters could not enter parts of the building over fears it might collapse, forcing crews to focus instead on preventing the blaze from spreading to nearby facilities and removing hazardous chemicals.…