Texas officials say all fires have been mostly extinguished at the Arkema chemical plant in the flood-ravaged Houston area after authorities launched controlled burns Sunday. Hurricane Harvey had damaged the plant, triggering several fires already.

The six remaining trailers were ignited at the Arkema plant in Crosby, Texas.

Following the controlled blaze, the Harris County Fire Marshal's Office said in a statement Sunday evening that "all nine trailers, which were filled with refrigerated organic peroxide, have burned."

Harvey's floodwaters swallowed the plant's backup generators, killing the plant's power — and refrigeration necessary to store chemicals that, "if not kept below a certain temperature, can explode and cause intense fires," as the Two-Way reported on Thursday.

Although "explosions" had been reported at the facility last week, Harris County officials explicitly said the trailers that had already caught fire and incidents of black smoke and "popping" were not in fact explosions.

As Bob Royall, assistant chief of the Harris County Fire Marshal's Office, said at the time:

"What will happen with these containers that are inside these box vans is, they will pop. And they will heat up, and they will catch on fire. And as such, they will burn with intensity until the fuel is consumed — and then they will die down again."

Meanwhile, NPR's Debbie Elliott said, "They're extremely flammable and burn intensely. A chain reaction of explosions is likely."

But Sunday's "proactive measures" quelled the risks of such unruly and potentially damaging fires, officials said.

"These measures do not pose any additional risk to the community," Arkema Inc. said in an update on the situation. Residents within 1.5 miles of the area had been evacuated.

The EPA released a joint statement with the Texas Commission on Environmental Quality and Unified Command in accordance with the decision to prevent greater risks:

"It is the understanding of personnel on the ground that the remaining trailers are at risk of catching fire over the next few days. Rather than risk additional damage to the facility or spreading into the surrounding area, the Crosby Volunteer Fire Department and the Harris County Fire Marshal's Office will perform a controlled burn of the material."

The fire marshal's office adds that federal and local agencies will continue monitoring the air and that "all data to date indicates no impact to air quality."

Copyright 2021 NPR. To see more, visit https://www.npr.org.