A second person died Friday from injuries received in an explosion at a chemical plant in Geismar, Louisiana, state police said.

The accident, whose cause is as yet unknown, killed another person on Thursday and left 73 injured, one of whom, 47-year-old Scott Thrower, died Friday in hospital.

Louisiana State Police Capt. Doug Cain named the plant employee who died Thursday as Zachary Green, 29.

The explosion at the Williams Olefins plant occurred at 8:30 a.m. Thursday, setting fire to at least two parts of the facility.

At the time of the explosion there were some 600 workers in the plant, police said.

The incident spurred the evacuation of more than 300 workers from the industrial area and led authorities to ask residents of the surrounding areas to stay home until the situation was under control.

According to the chief of state police, Mike Edmonson, the substance that fueled the post-blast blaze was propylene. EFE