Fire crews were still putting out embers and hot spots Sunday of a massive blaze at a recycling yard that authorities say drew the largest response in the Phoenix Fire Department’s history.

The fire began about 12:30 p.m. Saturday at a recycling yard, officials said, and quickly grew in strength, at one point drawing more than 200 firefighters from 10 agencies across the region.

Capt. Todd Keller, a spokesman for the Phoenix Fire Department, told The Washington Post on Sunday morning that more than 50 firefighters were still on the scene after crews had worked overnight. The blaze involved recycling and commercial facilities, including a tire business and a lumber yard. Five structures were destroyed.

“We do go on recycling fires, but for it to hit this level — it was the first time in history,” Keller said. “This is our first time experiencing this.”

One person was injured in the blaze, a firefighter who suffered a lower leg injury and was transported to a hospital in stable condition.

Keller noted it was largely cardboard and paper that burned. He said that he didn’t have information on the possible environmental impact but that authorities were advising people to avoid the area.

Don Falk, a professor at the University of Arizona’s School of Natural Resources and the Environment, said industrial fires involving materials that “do not occur in nature” can be concerning, but he said cardboard is a bit closer to plant fuels that spark wildfires.

The burning of twigs, leaves and other vegetation in wildlife is relatively benign, he said, compared with the burning of more hazardous industrial materials. He also noted the amount of flammable goods packed onto a site like a recycling yard can spell trouble.

“I’m quite sure that fuel loads in a recycling plant could be off the charts compared to a forest, which would explain why the fire behavior and heat output are so extreme,” Falk said in an email.

Crews were set to remain at the scene of the fire throughout Sunday, Keller said, with firefighters breaking open pallets of cardboard boxes at the recycling facility to extinguish any hot spots. He added that fires commonly break out at recycling yards and that the department had addressed fires at the same facility before.

The cause of the fire is unknown.

The recycling yard was identified as Friedman Waste Control Systems, according to the Arizona Republic. A call to the company was not immediately answered.

Arizona Gov. Doug Ducey (R) shared a prayer on Saturday for the firefighters battling the blaze, noting the high temperatures. The National Weather Service in Phoenix reported area temperatures as high as 108 degrees on Saturday.

Footage, videos and time-lapse images from local media outlets show giant plumes of dark smoke rising above the area. Throughout the day, smoke funneled through the otherwise clear sky.

The fire was so big it showed up on Weather Service radar, and the plume was visible from space, according to the NWS in Phoenix.

Keller said 150 people, including residential and commercial customers in the area, lost power until about 8:30 p.m. on Saturday. As of Sunday morning, he said, 21 people were still without power.