On a sunny Saturday, October 17, local resident Erin King was at Marina State Beach when she noticed three young women taking pictures and offered to help.

After they took photos of one another, the women insisted on taking one of King — and just as they did, a great white shark launched several feet out of the water directly behind them. "It happened so fast. I mean, it was just an instant," King told KSBW.

The resulting photobomb, caught on video, quickly went viral online.

The improbability of the moment is what made the footage a sensation: a shark leaping nearly fully from the water at the exact instant a camera was pointed at the shore.

KSBW reported that King said she did not think anybody else really saw the breach, and the clip's unlikeliness led many viewers online to claim it was fake — prompting officials to step in and verify that the event was real.

California State Parks independently confirmed that a shark matching the characteristics of a great white breached off the shore near Marina State Beach at the same time as the video.

According to KSBW, Mike Dippel, Chief Ranger for California State Parks, said the timestamp on King's video matched perfectly with a Surfline video of the same event, making it very likely the same shark. Posted shark notices went up at the beach under department protocol.

The video itself is the story: ABC News posted footage of the great white leaping out of the ocean off Marina Beach just as a beachgoer was taking a video, and TODAY aired the clip of the shark photobombing friends making a video at Marina State Park.

The sequence — friends posing, a shadow, then a shark erupting from the water — explains why the clip spread so rapidly across national outlets within a day.

Great white sharks frequent Monterey Bay seasonally, traveling to offshore waters near Hawaii before returning to California's coast in late summer and early fall, The Guardian reported.

Dippel told KSBW that October and the fall months are when white sharks migrate back to the Central Coast, urging swimmers and surfers to use caution. State Parks reminded visitors that sharks are an important part of the coastal ecosystem and that interactions between people and sharks are rare.

The advisory at Marina State Beach remained in effect through the end of the week, according to KSBW. The Guardian reported that great white sightings have increased along parts of the west coast in recent years, with changing ocean conditions and El Niño events influencing their migratory patterns.

Classified as vulnerable by the IUCN, great whites suffered population declines exceeding 90% in some regions during the 20th century, The Guardian noted, and a verified sighting so close to shore is a vivid reminder of a keystone species recovering its place along the California coast.