For a few days in late November 1937, it was the Southland's greatest attraction – a landslide in slow motion, 1.5 million tons of an Elysian Park hillside creeping toward the Los Angeles River bed. Cracks became crevasses as a half-moon-shaped landmass near Point Grand View sank inch-by-inch over the course of several weeks. Below, the slope crept across Riverside Drive and toward a strip of homes and shops. Sensational news reports, printed in papers and broadcast on radio nationwide, described it as a "moving mountain," and tourists came from afar to witness the geologic curiosity. One Oklahoma City police officer took a leave of absence to watch the slide. Two boys hopped freight trains from New York to see it. Some 10,000 sightseers came by the hour. Spectators pressed against police barricades along Riverside Drive, and enterprising vendors worked the throng like a baseball game, hawking peanuts, popcorn, and soda. Some even sold field glasses.

Sensational news reports, printed in papers and broadcast on radio nationwide, described it as a "moving mountain," and tourists came from afar to witness the geologic curiosity.

Everyone acknowledged that it was a sight to behold, but no one could agree on its cause. Some blamed seepage from the Buena Vista Reservoir atop the hill, or perhaps intake tunnels bored in 1885. Others speculated, somewhat implausibly, that pent-up gas pressure from an underground oil field had dislodged the hillside. Whatever the proximate cause, the landslide represented one episode in a continuing process of erosion as, over millennia, the Los Angeles River undercut the base of the Elysian Hills. Eventually, hillsides would give way as their slopes became too steep – a condition that construction of Riverside Drive might have exacerbated. What made this landslide such an attraction was its seemingly orderly nature. A violent process had been reduced to a crawl.

Order, however, suddenly turned to chaos on the night of Friday, November 26. At 10:35 p.m., the moving mountain roared downslope. Lights flickered and died as the landslide snapped transmission towers carrying 110,000-volt electric lines. Though, remarkably, no one died, the landslide was a genuine disaster. A 24-inch water main was severed, the Riverside Drive viaduct lay crushed beneath the hillside, and residents and shop owners were displaced as the city condemned several properties. And yet the slide – which more or less stabilized after its violent climax – continued to attract sightseers. The next day, an estimated crowd of 500,000 converged on the site, munching on popcorn and hoping the mountain would move again.

An aerial view of the landslide, which crushed the Riverside Drive viaduct and forced the city to condemn several homes and businesses. Courtesy of the Security Pacific National Bank Collection - Los Angeles Public Library.

The slow-motion landslide blocked Riverside Drive where the Golden State (I-5) Freeway now passes Elysian Park. Courtesy of the Los Angeles Times Photographic Archive, Department of Special Collections, Charles E. Young Research Library, UCLA.

Cracks slowly became crevasses, and then eventually the entire hillside slid in one violent moment on the night of Nov. 26. Courtesy of the Los Angeles Times Photographic Archive, Department of Special Collections, Charles E. Young Research Library, UCLA.

As the landslide crept toward the river, the forest atop the mass remained more or less intact. Courtesy of the Los Angeles Times Photographic Archive, Department of Special Collections, Charles E. Young Research Library, UCLA.

The landslide advancing across Riverside Drive. Courtesy of the Herman J. Schultheis Collection - Los Angeles Public Library.

Police estimated that half a million spectators came to see the 'moving mountain' the day after the landslide's violent climax. Courtesy of the Los Angeles Times Photographic Archive, Department of Special Collections, Charles E. Young Research Library, UCLA.

Amateur astronomers trained their telescopes on the moving mass. Courtesy of the Herman J. Schultheis Collection – Los Angeles Public Library.