The actress' 4-year-old son was found alone in a boat Wednesday.

The search for Glee star Naya Rivera has turned into a recovery mission and she is now presumed dead, according to authorities.

"Investigators believe Rivera drowned in what appears to be a tragic accident," according to a statement from the Ventura County Sheriff's Office.

The 33-year-old actress was reported missing Wednesday after a trip to Lake Piru in Ventura County, Calif. Rivera and her 4-year-old son, Josey Dorsey, rented a pontoon boat and were swimming in the afternoon. When the boat was not returned on time, the lake staff searched for it and found her sleeping son aboard alone, authorities said. "Rivera’s son told investigators that he and his mother had been swimming in the lake, and he got back in the boat, but Rivera did not," according to the Sheriff's Office.

“He’s in good health,” Ventura County Sheriff’s Department Capt. Eric Buschow told the Los Angeles Times of Rivera’s son. “The family is going through a very traumatic time right now.”

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The search for Rivera was suspended Wednesday night and resumed at daybreak Thursday. The Sheriff's Office later announced the search had turned into a "recovery mission."

"Approximately 50 sheriff’s personnel, along with a helicopter, boat crews, divers, and unmanned aerial vehicles searched the lake for five hours Wednesday evening, but Rivera could not be found," the Sheriff's Office statement said. "The entire shoreline and surface of the lake were thoroughly searched. Divers also searched under water in the area where the boat had last been seen. However, there was no sign of Rivera.

"The search resumed Thursday morning with divers experiencing less than one foot of visibility in the water in daylight. The difficult conditions have made the recovery operation a very slow process. The Los Angeles County Sheriff’s Department is assisting in the search with divers and sonar equipment. Approximately 100 personnel are participating in the mission on Thursday, including resources from neighboring counties and the United States Coast Guard."

Fox L.A. previously reported, citing officials, that Rivera's purse and an adult life jacket on that boat,  and her car was found in the parking lot.

Rivera gained fame for starring as Santana Lopez on Glee from 2009 to 2015, but she got her start on TV at an early age on programs like The Royal Family, Family Matters, and The Bernie Mac Show. After Glee, Rivera appeared on Devious Maids and Step Up: High Water. In 2013, she also released the track "Sorry" with Big Sean, whom she dated until 2014.

She was previously married to actor Ryan Dorsey from 2014 to 2018, and they shared custody of their son Josey. Rivera's last photo, from Tuesday, was a sweet close-up shot of her and Josey, with the caption "just the two of us."

EW has reached out to local authorities and Rivera's reps for more information.

This post has been updated with new information. 

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