Flaming debris fell down the steep mountainside as fire hit Rattlesnake Mountain, a popular hiking and climbing area in New Hampshire's White Mountains.

More than 70 firefighters battled the flames on Wednesday. By nightfall, more than nine acres had burned. Firefighters are returning Thursday to continue trying to put out the flames.

It's tough going for firefighters, who had to hike to the flames up a long steep trail.

Officials are not sure how the fire started.