A second person died on Friday as a result of an explosion that rocked the Williams Olefins petrochemical plant in Geismar, Louisiana, and injured more than 100 workers a day earlier...Williams Olefins CEO and President Alan Armstrong called the explosion "a tremendous tragedy." "A lot of us in this industry have spent much of our careers working to make it safe, so when something like this happens, honestly, it feels like a big failure," Armstrong told a news conference, his voice shaking...Parent group the Williams Companies Inc operates the plant and holds an 83-percent stake in it. The company had yet to identify the cause of the explosion and will launch an investigation as soon as all the remaining flammable hydrocarbons in the plant dissipated and it was safe to re-enter, plant manager Larry Bayer said. Louisiana Governor Bobby Jindal on Thursday vowed to hold responsible whoever may be at fault.