In this Monday, July 22, 2019, photo, an air tanker drops retardant on a ridge overlooking the North Peak neighborhood as the Museum Fire burns north of Flagstaff, Ariz. (Photo: AP)

Rain falling Wednesday in a forested Arizona city helped crews battle a wildfire that has raged for days in a scenic mountain pass overlooking the city, officials said.

But in Idaho, a wildfire burning on the sprawling grounds of the Idaho National Laboratory nuclear research site grew and pushed closer to buildings.

It was not immediately clear what the threatened buildings contained, but laboratory spokeswoman Kerry Martin said monitoring showed radiation at normal levels at the nation’s primary federal nuclear research facility.

In Arizona, up to 1 inch (2.5 centimeters) of rain was allowing ground crews to directly attack the fire, extinguish flames and build containment lines in an area where nearly 3 square miles (7.6 square kilometers) have burned since Sunday, said fire management team spokesman Steve Kleist.

Forecasters warned of possible flooding because of thunderstorms expected to drench the area on Wednesday and Thursday in the zone scarred by the fire, which has prompted anxious residents to pack up prized possessions.

About two dozen homes have been evacuated and residents of 5,000 homes were previously told they might have to leave.

Gov. Doug Ducey declared a state of emergency Tuesday, freeing $200,000 in state funding for the effort to battle the blaze in the Coconino National Forest surrounding Flagstaff, a popular mountain getaway in the largest Ponderosa pine forest in the US.

The city and Coconino County issued emergency declarations a day earlier. The firefighting cost to date is $2.1 million, said incident Commander Rich Nieto.

On Tuesday, Flagstaff residents peered through binoculars to get a closer look at the fire that sent plumes of smoke into the air and ash into yards while helicopters buzzed overhead.

Kim Meehl’s car and her husband’s truck were packed with photo albums dating to when she was a teenager and other precious items.

She reserved the back of the car for dogs, cats and rabbits after taking goats to another pasture.

“They’re hanging with us until we have to go,” she said. “I don’t know for sure, but I’m hoping, hoping, hoping. It looks better.”

Justina Ferrara and her grandmother readied for possible evacuation by gathering documents, photographs and treasured family heirlooms like Kachina dolls and Native American blankets.

Ferrara was more worried about the mountain than her home.

“It’s the devastation to what’s going on in the vegetation,” she said. “It’s not going to come back anytime soon.”

In Idaho, the nuclear research site includes reactors and research materials, as well as facilities for processing high-level nuclear waste and other radioactive waste. Martin, the laboratory spokeswoman, said the wildfire is not currently near the site’s waste processing facilities.

Wildfires are frequent at the high desert site and the Martin said the fire appeared to be “in good shape” Wednesday morning.

An evacuation order for non-essential laboratory employees that went into effect Tuesday was still in place on Wednesday.