CROSBY, Texas — The U.S. Chemical Safety Board says it will investigate a fire at a Houston area chemical plant that killed one worker and injured two others.The Chemical Safety Board said Wednesday it will join other agencies probing the cause of Tuesday’s blaze at a KMCO chemical plant in Crosby, about 25 miles (40 kilometres) northeast of Houston.The safety board, an independent federal agency that investigates industrial chemical incidents, is also probing the March 17 blaze at a petrochemical storage facility in nearby Deer Park .Rachel Moreno, with the Harris County Fire Marshal’s Office, says her agency’s investigators haven’t been able to enter the plant because of ongoing clean up and emergency operations.Harris County officials say ongoing air monitoring shows no health risks to the area around the plant.The Associated Press