Chemical leak at a West Virginia plant kills 2 people and sends 19 more to hospital, officials say

INSTITUTE, W.Va. -- A chemical leak at a West Virginia plant killed two people and sent 19 others to the hospital, authorities said.

The leak occurred at the Catalyst Refiners plant, a silver recovery business in Institute, as workers were preparing to shut down at least part of the facility, Kanawha County Commission Emergency Management Director C.W. Sigman said.

A chemical gas reaction occurred at the plant involving nitric acid and another substance, Sigman said.

The reaction caused "a violent reaction of the chemicals and it instantaneously overreacted," Sigman added.

Among the injured were seven ambulance workers responding to the leak, officials said.

This is a developing story. Please check back for updates.