GARYVILLE, La. (AP) — Crews were still working to suppress flare-ups Saturday as a fire at a Louisiana oil refinery burned for a second day along the banks of the Mississippi River, while residents worried about health effects from the fumes and black smoke.

Tests have so far found “non-detectable air quality impacts” from Friday’s massive fire, Marathon Patroleum said in a emailed statement Saturday. The state Department of Environmental Quality and a third-party contractor were conducing the tests.

The company said two people were injured and 10 others evaluated for heat stress. The fire damaged two giant storage tanks for naphtha, a component in the production of gasoline and jet fuels.

On Friday, orange flames belched a column of thick smoke over the facility in Garyville, about 30 miles (48 kilometers) northwest of New Orleans, forcing residents of the mostly rural area to evacuate within a 2-mile (3-kilometer) radius.

“You look outside your house and the sky is black,” Hilary Cambre, who lives right next to the refinery, told WWL-TV on Friday. He and other residents said they felt nauseous, dizzy and had headaches.

People with respiratory conditions should avoid going outdoors if they live near the facility, Dr. Rustin Reed with Tulane University’s School of Public Health and Tropical Medicine told the television station.

Some schools locked down Friday and two nearby schools served as evacuation centers, the station reported. One resident described police officers driving around with loudspeakers alerting people to the mandatory evacuation.

The cause of the fire will be investigated, the company said.

People who’ve been affected by the fire and need assistance can call the company’s toll-free hotline at 866-601-5880.