Former Glee actor Naya Rivera raised her arm and called for help as she drowned while boating with her son, according to a post-mortem report.
Rivera, best known for playing Santana Lopez on TV musical-comedy Glee from 2009 to 2015, had been with her four-year-old son, Josey Hollis Dorsey, on Lake Piru, northwest of Los Angeles, on 8 July.
The report by the Ventura County Medical Examiner said the 33-year-old had helped her son back into the boat after swimming and he had noticed her "put her arm up in the air and [yell] 'help'" before she "disappeared in to the water".
The boy was found sleeping on the boat later that afternoon and Rivera's body was found floating in the lake five days later.
Rivera "knew how to swim well", according to the report, and the man who had rented her the boat said she declined a life jacket - he had put one on the boat anyway.
The report also revealed Rivera had previous problems with vertigo, a recent sinus infection and a small amount of prescribed amphetamines in her system, but none of these were described as factors in her death.
She also had also taken small amounts of an anti-anxiety drug and an appetite suppressant.
After her body was found, Sheriff Bill Ayub had said Josey told detectives the pair went swimming and she boosted him onto the deck before he looked back to see her disappear under the water.
The sheriff said their theory was that the boat drifted as they swam and she "mustered enough energy to get her son on board, but not enough to save herself".
Rivera's body was found seven years after Glee co-star Cory Monteith died at 31 from alcohol and heroin.
Another Glee star, Mark Salling, killed himself in 2018 at age 35 after pleading guilty to child pornography charges.
Former Glee star Blake Jenner has said he takes "full responsibility" for having abused his ex-partner "emotionally, mentally and physically".
Jenner played Ryder Lynn in the Fox musical comedy-drama series.
His Instagram post, which does not name his ex-partner, follows Supergirl star Melissa Benoist posting last year about domestic violence and an anonymous ex.
US news publications and a surge of social media posts have suggested they were each referring to each other.
"Over the past 11 months, I have been thinking about how to address a personal situation made public in late-2019," wrote Jenner.
"Throughout that time, I reflected on a period in my life that I had previously kept in the darkness out of shame and fear, but I know this is something that needs to be addressed, not just publicly, but also privately with the individual directly affected and with myself."
Naya Rivera: Wrongful death lawsuit filed over Glee star's drowning
A wrongful death lawsuit has been filed over the drowning of Glee actress Naya Rivera, who died during a boating trip with her young son in July.
The suit was filed by Rivera's ex-husband and on behalf of her estate over the accident on a California lake.
It blames the local authority and the managers of Lake Piru, north-west of Los Angeles, where the accident happened.
It alleges swimmers were not adequately warned of the risks of swimming there.
The late 33-year-old actress was best known for playing cheerleader Santana Lopez in Glee.
The lawsuit was filed on behalf of her son by Rivera's ex-husband and the boy's father, Ryan Dorsey.
It alleges that the boat rented by Rivera was "not equipped with a safely accessible ladder, adequate rope, an anchor, a radio, or any security mechanisms to prevent swimmers from being separated from their boats". It also said it did not have any flotation devices.
It also alleges there were no warning signs at the lake alerting swimmers to potentially dangerous conditions such as strong currents, low visibility and changing water depths.
The local authorities have not yet commented on the lawsuit.
Rivera had rented a pontoon boat with her son - aged four at the time of the accident - at Lake Piru on 8 July.
The child was found alone and asleep in the boat by a leasing agent after it was not returned, prompting a search for the actress. Her body was found a few days later and her death was later declared to have been accidental.