If flames were to reach the top of Mt. Wilson, home to the region's TV and FM radio transmitters, what would happen?
Severe damage could disrupt cellphone service, as well as television and radio programming for those who receive signals over the air. It also could interrupt some emergency law enforcement communications.
But Los Angeles police and fire departments do not use the tower, and neither does the Los Angeles County Sheriff's Department.
Mt. Wilson is home to more than two dozen towers that occupy its peak just north of Sierra Madre. It supports antennas that beam signals for television and FM radio stations throughout the region. The fire also threatens the historic solar observatory atop the mountain, which houses multimillion-dollar astronomy projects for UCLA, USC and UC Berkeley. Georgia State University also operates a $20-million facility and a powerful telescope array at the observatory.
"There's a lot of dollar value in those towers and of course, what they mean to broadcasters in Southern California," said Harold McAlister, director of the nonprofit Mt. Wilson Institute, which runs the observatory. "It's one of the major communication centers for this part of the country."
KCBS-TV Channel 2 and KABC-TV Channel 7 said that viewers with cable or satellite television will still receive a signal, but those who get theirs over the airwaves might lose their connection.
"A lot of people think of an observatory as one dome, but Mt. Wilson Observatory is actually a 40-acre tract of land with 50 to 60 buildings on it," McAlister said. "None of that stuff is portable, and to move telescopes out of there takes many weeks. We're strictly at the mercy of nature and the great competence of the firefighters."
The observatory was founded by George Ellery Hale in 1904, and its first telescopes were transported up the nine-mile Mt. Wilson toll road on the backs of burros in pieces that weighed hundreds of pounds each. Now, the observatory lets visitors view space through its 60-inch telescope, which has been in place since 1908.
The observatory was also a home to Edwin Hubble, who used the famed 100-inch Hooker telescope in the 1920s and recognized that the faint smudges in the sky called nebuli were in fact distant galaxies. Observing that these galaxies were moving away from one another, he determined that the universe was expanding. Hubble's theory, combined with Einstein's theory of relativity, concluded that the universe was created at a specific point in time, later called the Big Bang.
Flames also had damaged emergency communications equipment on Mt. Lukens, north of La Crescenta.
"It is changing minute by minute," McAlister said of the situation late Sunday. "In terms of what could happen, anybody in the L.A. Basin that watches television broadcast rather than cable or satellite will lose their television connection. It really is a major communications link for Southern California up there.
"It is where the modern universe was discovered," he said. "It is a precious scientific site that is invaluable."
Times staff writers Rong-Gong Lin II and Anna Gorman contributed to this report.