A water treatment facility at the North Rim had been compromised by the fire, causing chlorine gas to fall to the bottom of the Canyon.

In this secluded paradise, mail still arrives by mule, turquoise cascades tumble into travertine pools, and time flows at the pace of the river.

What fueled the explosive growth of the Dragon Bravo Fire was a mix of gusty winds, dry air and above-normal heat – weather conditions experts described as atypical for this time of year, when monsoonal moisture typically tamps down wildfire risk across Arizona.

The resulting Nankoweap landslide would have dumped enormous limestone boulders into the river corridor, creating a temporary dam and a lake whose surface may have reached 940 meters elevation before water overtopped and eroded the blockage, likely within 1,000 years.

The congressman is the latest lawmaker asking why the Dragon Bravo fire was not immediately extinguished when it was ignited by lightning on July 4.

The fast-moving fire destroyed a historic lodge and dozens of other structures in the Grand Canyon National Park.

Wildfires can burn and spread differently depending on what vegetation they burn. The two fires in northern Arizona have varied landscapes. Ponderosa pine trees grow near the North Rim of the Grand Canyon and can live for hundreds of years.