PAULINA, La. (AP) — Some of the evacuated residents from the south Louisiana community of Paulina were allowed to return home Thursday, a day after they were told to abandon the area because of sulfuric acid that leak from a derailed tank car.

But others with homes closer to the spill site were told they would have to wait while emergency personnel tested soil and building surfaces that could have been contaminated by vapors from the spill. Hotel stays were authorized for a second night for evacuated residents.

St. James Parish Sheriff Willy Martin said any affected homes would have to be washed with agents to neutralize the acid residue. And anyone who left windows or doors open would have to have their interior homes inspected for contamination before they could permanently return.

About 200 homes were under Wednesday’s evacuation order. Parish President Pete Dufresne said the evacuation order would be lifted on a street-by-street basis.

Paulina is a little more than 40 miles (64 kilometers) west of New Orleans.

Sulfuric acid is extremely corrosive and inhaling fumes from the spill can damage lungs. Video from the scene shown on social media showed the leaking car and bubbling trail of liquid leading away from the tracks.

The cause of Wednesday’s derailment was under investigation.

Evacuations were called soon after the Wednesday afternoon derailment of several Canadian National railroad cars. There were no reports of injuries.

The damaged car was one of six that derailed. State police spokesman Christian Reed said the damaged rail car was carrying 20,000 gallons (75,700 liters) of the chemical.

Crews worked Thursday to upright the damaged car and prevent more acid from spilling. Cleanup involved the use of chemicals to neutralize the acid and the hauling away of contaminated material.

Overnight, workers contracted airboats to disperse vapors from the area to make it safer for workers. Martin said authorities would work with evacuated residents who quickly abandoned the area to allow them, when safe, to temporarily return home to retrieve personal items and pets.