FORT WORTH, Texas >> The North American subsidiary of a French chemical manufacturer and two senior staff members were indicted today in connection with last year’s explosion at the Crosby, Texas, plant in the wake of Hurricane Harvey.

Arkema North America, its CEO Richard Rowe and plant manager Leslie Comardelle were charged in the Harris County indictment with “recklessly” releasing chemicals into the air. The charge carries up to $1 million in fines and five years’ imprisonment.

“Indictments against corporations are rare,” Harris County District Attorney Kim Ogg said in a statement. “Those who poison our environment will be prosecuted when the evidence justifies it.”

After Arkema’s plant lost power, its organic peroxides began heating and decomposing. The compounds, used in a variety of products from plastics to paints, caught fire and partially exploded, sending plumes of smoke skyward.

First responders and neighbors said they were sickened after the incident.

Arkema spokeswoman Janet Smith today said the corporation would fight the indictment, citing a U.S. Chemical Safety Board report released last May that credited it for having safeguards that likely would’ve worked in a low-level flood event.

Arkema officials have insisted since the incident last August that they planned as best they could but that the rainfall was unprecedented.

The agency’s lead investigator Mark Wingard said Arkema crews worked “to the best of their ability” to keep equipment that cooled and stabilized its organic peroxides from losing power as six feet of water engulfed the plant.

An internal watchdog at the Environmental Protection Agency announced Thursday that it will audit the agency’s response following several high-profile accidents and spills after the historic storm, including the explosions and fire at the Arkema plant.