An acid spill Friday afternoon near Indianapolis led to an explosion that injured workers at a Rolls-Royce plant.
Authorities with the Indianapolis Fire Department confirmed that the transferring of nitric acid at the West Township-based facility caused the incident.
The department's spokesman Patrick Pruitt says that the highly explosive chemical was being removed from a 250-gallon tank.
Workers on the manufacturing floor were transferring the acid when the tank unknowingly started to leak.
A “nitric acid escape” eventually caused a chemical cloud to form inside the building, says Rolls-Royce VP of Communications Joel P. Reuter.
Authorities say they are unsure about how much acid was inside the tank at the time of the spill.
Fire departments from three different cities responded to the acid explosion. A hazardous material team also appeared on the scene to minimize the damages nitric acid is known to cause-which are respiratory problems and severe burns.
Nearly 500 workers were immediately evacuated away from the facility. However, nine employees sustained injuries from the blast.
One was treated on scene while the other eight were taken to local hospitals for acid exposure.
The victims' conditions have now been labeled as stable.
Fire crews were able to subdue the chemical cloud later that afternoon and informed the company that it was safe to reenter the plant.
Pruitt told NBC News: "Now it's just a matter of making sure that we ... get that material neutralized."
The facility decided to cancel second shift just to take extra precaution. Workers were allowed to return to work and continue their shifts Saturday.
The definite cause of the explosion is still unclear and is being investigated by authorities.
The Rolls-Royce Company in Indianapolis is commonly recognized for its aviation and marine production at the plant. The company has more than 10 other facilities located in the state.
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