GRAND PRAIRIE, Texas (AP) — Firefighters doused the last hot spot Thursday after a massive fire a day earlier at a Dallas-area plastics factory sent a dense column of toxic black smoke over North Texas, officials said.

The last of the fire at the Poly-America plant in Grand Prairie, which started early Wednesday, was extinguished Thursday afternoon, said Grand Prairie Fire Department spokeswoman Claudia Garibay. Damage was confined to plastic sheets stored in a yard downwind from the plant building, which wasn’t damaged, she said.

Fire officials have said a power line fell in a storage yard, igniting plastic sheeting. Garibay said the cause remains under investigation. No injuries were reported.

Poly-America is headquartered in Grand Prairie and specializes in products made from polyethylene, such as trash bags, drop cloths and plastic sheeting, according to the company’s website.