LAKE PIRU (CBSLA) — As the search for “Glee” actress Naya Rivera continued Thursday, Ventura County officials released the 911 call made after her 4-year-old son was found on a boat on the lake.

A boat, believed to be the one rented by missing actress Naya Rivera, is docked and roped off with police tape at Lake Piru on Wednesday. (Photo by Amy Sussman/Getty Images)

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“The emergency is, we have a missing person,” an employee of the rental boat business said. “We found a little girl in one of the boats by herself, and her mom is nowhere to be found.”

The caller initially assumed Rivera’s child, a 4-year-old boy, was a little girl because of his long hair.

The Ventura County Sheriff’s Department also released security video of 33-year-old Rivera and her child getting into the boat together Wednesday afternoon.

“They were able to conclude that they were the only two on the boat when the boat left the dock,” Sgt. Kevin Donoghue, of VCSD, said.

Rivera’s son was found Wednesday afternoon sleeping in the boat wearing a life jacket and an adult-sized lifejacket was also found in the boat.

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“We’ve had no indication, after talking to her son, that Ms. Rivera made it to shore,” Donoghue said.

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Deputies said Rivera had experience navigating Lake Piru, but even the most experienced swimmers could succumb to the lake’s dangerous rip currents or get tangled up in debris.

“Under the water, it’s a lot by feel,” Max O’Brien, one of the divers, said. “There’s a lot of shrubbery and sticks that we have to break through as we’re going through, so it’s kind of a braille search.”

Officials Thursday said the search and rescue effort had turned into a search and recovery effort, with Rivera presumed dead.

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Dive teams left the lake as night fell, though deputies will remain on site. Divers will resume the water search Friday morning.