Firefighters explain fierce battle to save historic Mount Wilson Observatory amid raging Bobcat Fire

MOUNT WILSON, Calif. (KABC) -- As flames from the Bobcat Fire inched closer to the famed Mount Wilson Observatory and several other communication towers earlier this week, firefighters worked around the clock to protect the historic site.

Crews fired flares to strategically burn areas in the Mount Wilson area. Firefighters said backfires were set on Tuesday while taking advantage of reduced winds, lower temperatures and higher humidity to carve out a containment line after flames came within 500 feet of the landmark.

Bobcat Fire: Flames encroaching on Mount Wilson

The Bobcat Fire is encroaching on Mount Wilson, home to many of the towers that broadcast TV and radio signals to the Los Angeles area.

Crews also attacked the blaze, which is one of the largest ever in Los Angeles County history, from the air. Pink foschek stained the ground where crews worked to protect the observatory as well as radio and television communication towers.

Mount Wilson Observatory, which played a key role in advancing 20th century astrophysics since it was founded in 1904. Mount Wilson is also home to an estimated $1 billion worth of transmission towers, a key site for TV, radio and government agencies.

"This is the last remaining fuel that would burn. So that's why we're really confident today that Mount Wilson is out of that danger area," said Andrew Mitchell with the U.S. Forest Service.

RELATED: Bobcat Fire burns nearly 114,000 acres as containment grows to 50%

The raging Bobcat Fire is 50% contained and has burned 113,986 acres, becoming one of the largest fires ever in Los Angeles County.

The fire has burned for more than two weeks, scorching over 113,000 acres at 50% containment. Flames have pushed out of the Angeles National Forest and toward foothill communities.

"Half the time it's very intense, and half the time you're preparing for it to be intense," said Los Angeles County Fire Capt. Dave Gillotte.

A damage assessment by L.A. County officials shows nearly 30 homes and more than 20 other structures were destroyed.

The cause of the blaze remains under investigation. However, SoCal Edison says federal investigators are looking into whether the utility's equipment sparked the fire in the Cogswell Dam area.

Firefighters says they're taking advantage of reduced winds, lower temperatures and higher humidity to hold the containment line.

Fire official say so much progress has been made that the estimated date for full containment has been moved up to Sept. 30.

VIDEO: Bobcat Fire spawns 'smokenado' near Big Pine amid strong winds

A "smokenado" was captured on camera twisting into the sky near Big Pines as the nearly 100,000-acre Bobcat Fire continued to rage.