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

The White Sage Fire near the North Rim has grown to more than 19,000 acres, authorities said, while the nearby Dragon Bravo Fire has burned at least 5,000 acres.

Visitors and staff at two national parks in the U.S. West have been evacuted because of wildfires. Officials at Black Canyon of the Gunnison National Park in Colorado say the park closed Thursday morning after lightning sparked blazes on both rims.

Authorities increased the size of the evacuation zone for the White Sage Fire north of the Grand Canyon on Friday morning.

Officials evacuated Jacob Lake and the North Rim of the Grand Canyon was closed to visitors because of the fast-moving White Sage wildfire.

Hundreds of visitors and residents were evacuated from the North Rim of Grand Canyon National Park this week as two wildfires advanced toward the park.

The North Rim of the Grand Canyon is closed "until further notice" as a wildfire rages in the area, park rangers announced on Thursday.

The Coconino County Sheriff's Office helped evacuate people from an area north of Jacob Lake and campers in the Kaibab National Forest nearby.

The White Sage Fire was burning in Arizona bout 15 miles southeast of Fredonia in Coconino County and north of the Grand Canyon State Park.