HOUSTON (CBSDFW.COM/AP) — The North American subsidiary of a French chemical manufacturer and two senior staff members have been indicted 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 Friday’s Harris County indictment with “recklessly” releasing chemicals into the air. The charge carries up to $1 million in fines and five years’ imprisonment.

After Arkema’s plant lost power, its organic peroxides began heating and decomposing. The compounds, used in products including 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 on Friday said the corporation would fight the indictment.

Officials with the U.S. Chemical Safety Board said the chemical plant didn’t account for high flood waters and lacked a plan for the Harvey floods despite years of severe weather in the Houston area and a 2016 warning from its insurance company.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)