Naya Rivera died of an accidental drowning while swimming in a Southern California lake with her young son, authorities confirmed Tuesday.
An autopsy concluded that Rivera's cause of death was "consistent with a drowning" and that neither drugs nor alcohol were found in her system, according to the Ventura County Medical Examiner's Office.
The Glee actor's body was recovered Monday after a five-day search following her disappearance while boating with her son on Lake Piru last week.
Rivera, 33, was reported missing after a boater found her 4-year-old son, Josey, on the lake, sleeping alone in the pontoon boat she had rented that day.
Ventura County Sheriff Bill Ayub said in a news conference Monday that Rivera's son had been wearing a life jacket, while an adult's life jacket was found on the boat.
"We know from speaking with her son that he and Naya swam in the lake together at some point during their journey," Ayub said. "It was during that time that her son described being helped into the boat by Naya, who boosted him onto the deck from behind. He told investigators that he looked back and saw her disappear under the surface of the water."
Ayub said investigators believe Rivera had used all of her energy to help her son back into the boat as it began to drift away from them, but was not able to save herself.
"We believe it was midafternoon when she disappeared," Ayub said. "The idea perhaps being that the boat started drifting, it was unanchored, and that she mustered enough energy to get her son back into the boat, but not enough to save herself."
Following the recovery of her body, Rivera's former Glee cast members and other celebrities paid tribute to the actor on social media.
"How can you convey all your love and respect for someone in one post? How can you summarize a decade of friendship and laughter with words alone?" Chris Colfer, who played Kurt Hummel on Glee, wrote on Instagram. "If you were friends with Naya Rivera, you simply can’t. Her brilliance and humor were unmatched. Her beauty and talent were otherworldly.”
On Tuesday, Glee creators Ryan Murphy, Brad Falchuk, and Ian Brennan also remembered Rivera as "one of the most talented, special stars" they had ever worked with, and announced the creation of a college fund for her son.
“She was warm and caring and fiercely protective of the rest of the cast," the team said. "She was tough and demanding. She was fun. She was kind. She was generous."