For the second time in the past few days, the Occupational Safety and Health Administration (OSHA) has launched an investigation into a chemical plant explosion in Louisiana. On Thursday, a plant in Geismar, La., exploded, killing one person and injuring 73. On Friday, a blast in Donaldsonville, La., killed one person and injured seven. The plant that exploded on Thursday hadn't been inspected by OSHA in 20 years. It is not yet known when the last inspection was done at the Donaldsonville plant.

OSHA officials were expected to visit the plant, owned by CF Industries, as soon as the state's hazardous materials unit could guarantee that the location was safe to visit. Police identified Ronald “Rocky” Morris Jr., 55, of Belle Rose, La., a 34-year employee at the plant, as the victim.

CF Industries produces ammonia and nitrogen-based fertilizers at the facility, but the company said there were no hazardous materials produced at the plant. Lou Frey, the vice president and general manager of the facility, blamed the blast on an equipment rupture as nitrogen was being offloaded from a tanker truck.

In 2000, the same Donaldsonville plant was the site of an explosion that killed three people and injured nine. OSHA fined CF Industries nearly $150,000 that year for 14 alleged safety and health violations, most of which were described as serious. CF Industries paid those penalties and did not contest the citations.