The Tunnel Fire swept across Sunset Crater Volcano National Monument on Tuesday, April 19/Inciweb

Flames from the Tunnel Fire were said to be burning Friday in Sunset Crater Volcano National Monument in Arizona, three days after a firestorm swept across the monument, destroying a number of buildings and vehicles, the National Park Service said Friday evening.

How much damage was done when the wildfire swept the park Tuesday was impossible to say, as park staff hadn't returned to assess the damage due to the "active fire in the monument," said Naaman Horn, a Park Service spokesperson in Denver.

The Tunnel Fire was reported Sunday morning roughly 2.5 miles from the monument, which is located northeast of Flagstaff.

By Tuesday morning, "high winds pushed the fire north and east through Sunset Crater Volcano National Monument," said Horn in an email. "Park staff were quickly notified of the impending danger and park visitors and staff were evacuated by early afternoon. The fire reached the southwestern boundary of the monument approximately 4 p.m. Tuesday and by late evening the fire had passed through the entire monument, with the fire continuing beyond in a northeasterly direction.  

"Given the magnitude of the fire, the visitor center and adjacent park housing remain thankfully standing and intact. A brief initial assessment determined that several outbuildings, equipment, and vehicles were destroyed," the spokesperson added. "Further assessment when conditions allow will likely reveal substantial damage to trails and roads. The fire appears to have burned very quickly through most of the monument and as such the burn pattern is 'mosaic' with many trees only singed vs. completely scorched."

Naaman said the fire swept across the entire national monument, though in a patchy fashion. While the flames had not reached nearby Wupatki National Monument, the spokesperson said that park had been evacuated and closed to the public.

Sunset Crater sprawls across a volcanic landscape of cinders and lava beds, which likely played a role in the course the flames took across the park.

On Friday the Tunnel Fire was about 14 miles northeast of Flagstaff and measured at more than 21,000 acres and was just 3 percent contained. Strong, gusty winds were in the forecast, complicatred the task for the nearly 400 firefighters battling the blaze.