CONVENT (WBRZ) - Sources said workers were testing the readiness of the Nucor plant in St. James Parish when there was a structural failure of a storage dome, causing the dome to collapse late Wednesday afternoon.

The sound made people believe there was an explosion, which was the initial report to emergency responders.

Exactly what failed has yet to be determined.

"Nucor will have teams out to determine the root cause," Eric Beroche, the Director of the Office of Emergency Preparedness for St. James Parish said..

No one was hurt and no hazardous chemicals were released.

The plant, which is under construction, was set to open in about two to three weeks. Leaders weren't sure about how the timetable would be impacted by the event. They referred questions to the company. A company representative never returned calls.

Nucor is set to spend about $3 billion on its facility in Convent. 

Image: WBRZ