More than 72 hours after Hurricane Ida made landfall, plumes of dark black smoke were still rising from four towers at the Shell plant in Norco, Louisiana. Enormous flames billowed out of these towers in the heart of the petrochemical region known as “Cancer Alley,” and a thick smudge of smoke floated across the sky away from the plant.

The refinery has a history of significant flaring and compliance issues. In the last few years, the U.S. Department of Justice and the Environmental Protection Agency have fined it for flaring more than allowed — and the facility has run into trouble with state authorities for failing to prevent emissions of sulfur dioxide and other toxic chemicals.

At least as of Thursday, it remained unclear when the flaring would stop.

“As a result of impacts related to Hurricane Ida, Shell’s Norco Manufacturing site is without electrical power,” said Cindy Babski, a spokesperson for Shell. “While the site remains safe and secure, we are experiencing elevated flaring. We expect this to continue until power is restored.”

It’s unclear exactly what the facility is flaring and how much of it is being spewed into the air. The company is required to report unusual flaring activity to the Louisiana Department of Environmental Quality, the agency responsible for overseeing air quality in the state. A spokesperson for the agency told Grist that since the department’s records office had suspended normal operations due to the hurricane and loss of power, they weren’t sure if Shell had submitted flaring reports.

These flares can be avoided with adequate planning and preparation. By shutting down operations in a controlled manner well ahead of the hurricane making landfall and installing equipment that prevents excess flaring, refineries can prevent enormous pollution events during hurricanes.

Read the full article about insufficient hurricane preparedness by Naveena Sadsivam and Jake Bittle at Grist.