Fire threat eases at Mount Wilson after five-day battle for survival

Mount Wilson, the home of the famed observatory and the antenna farm that services Southern California broadcasters, may have escaped destruction as the city’s largest wildfire inched past it. Changing weather conditions, however, still posed a threat to the mountaintop facility and firefighters remained on guard as of Thursday.

After evacuating everyone from Mount Wilson earlier, firefighters returned by midweek in an attempt to save it. There were 150 people working in the area — setting backfires, clearing brush from around the facilities and repairing pumps on the 750,000 water tanks that serve the astronomical observatory.

The Mount Wilson Observatory, a 100-year-old historic site, is where Edwin Hubble and his assistant Milton Humason used a 100in telescope to determine that our Milky Way is one galaxy among countless others. Their data led to the formulation of the Big Bang Theory. Mount Wilson was once the largest observatory in the world.

An enormous airplane, a World War II-era Martin Mars flying boat, flew over Mount Wilson to dump 7500gal of flame-retardant gel over the facilities there. Higher humidity and a brief absence of wind gave firefighters time to establish a larger perimeter around the facility.

The situation was described as “touch and go,” with fire still blazing below Mount Wilson. A sudden change in weather could place the facility in danger again, though now it is more defensible with the larger clearing around it.

Broadcast antennas for 22 Los Angeles TV stations and 25 FM radio stations are located on Mount Wilson. There are no AM radio stations. Dozens of technicians who service these broadcast towers were pulled off the mountain earlier.

Damage to these antennas or the power lines servicing them will not affect the majority of TV viewers, who get their signals through cable or satellite services. However, the stations told over-the-air viewers that if fires hit their towers, they should watch programming streamed to the stations’ Web sites.

Radio stations did the same; for example, KPCC/89.3 FM, one of those stations ready with a backup plan, created a webpage to aggregate the latest fire information from a variety of news sources.

The $20 million observatory is a sprawling complex that now services USC, UCLA, UC Berkeley and a number of other higher education institutions.

The “Station Fire,” which some are dubbing this particular L.A. wildfire, has burned more than 42,000ac in Los Angeles County and caused the death of two firefighters. Some 2800 firefighters remain engaged in the battle.