The National Park Service is defending its handling of a lightning-sparked wildfire that destroyed the nearly century-old Grand Canyon Lodge and dozens of historic cabins, saying containment lines had been built around the blaze and crews were prepared to conduct defensive firing operations.

Wildfires burning at or near the Grand Canyon's North Rim are still raging as strong winds, high heat and low humidity persist.

A wildfire burning in Grand Canyon National Park triggered a chlorine gas leak Friday afternoon after flames reached a water treatment facility.