An explosion at the Williams Olefins chemical plant in Geismar, La., on Thursday left one dead and at least 73 injured.

Smoke billowed from the building at 8:37 am at the plant along the Mississippi River as a large blast occurred, according to Reuters. It is only one of 12 plants along a 10-mile stretch of the river.

Witnesses reported seeing flames as high as 200 feet as workers stumbled over the fences surrounding the building, according to CBS News. It was reportedly caused by the petrochemical propylene.

The body of Zachary C. Green, 29, of Hammond, was found after the fire, said Trooper Jared Sandifer.

Christina Stephens of the Louisiana Health Department said at least 75 people were injured in the explosion and fire, which blazed for three hours after the initial blast.

“Generally they were people who came in with burns, cardiac issues and blunt trauma,” said Stephens.

“Once the investigations are done, once there's a responsible party, they will absolutely be held responsible,” said Louisiana Governor Bobby Jindal, who went to the site and met with emergency workers, according to CNN.

Twitter: Wave3News Twitter