Details about how she ended up in the water are still unclear. According to BBC News , an autopsy report at the time revealed that Natalie was found with bruises on her body and arms and a facial abrasion on her left cheek, bringing into question whether Natalie's death was the result of foul play. A woman on a nearby boat also told police that she had heard a woman screaming that night, according to the Los Angeles Times .

Now, a new HBO documentary, Natalie Wood: What Remains Behind, by Natalie's daughter, Natasha Gregson Wagner, is reigniting interest in the case. In the documentary, Natasha interviews her stepfather, Robert, who was on the boat the night Natalie died, about allegations that he may have had something to do with her death. (Worth nothing: Natasha's biological father is Richard Gregson, who was briefly married to Natalie. After they got divorced, she remarried Robert, who was also her first husband.)

Watch this sneak peak of Natalie Wood: What Remains Behind:

Natalie's cause of death was originally ruled as an "accidental drowning," but in 2011, the investigation into her death was reopened after the boat's captain, Dennis Davern, who was also there the night Natalie died, publicly stated that he had lied to police about the events that occurred that night. Then, in 2012, Los Angeles' chief coroner amended Natalie's death certificate to read that she had died by "drowning and other undetermined factors," not just an "accidental drowning," according to The Hollywood Reporter .

Here's everything the public does know about what happened to Natalie Wood the night of her deathand what has transpired since.

Natalie may have been intoxicated when she drowned.

The initial investigation into the Rebel Without A Cause star's death found that she had died while "slightly intoxicated," according to the New York Times . Thomas T. Noguchi, the Los Angeles county medical examiner at the time, theorized that Natalie was under the influence of alcohol when she slipped and fell into the water as she tried to board a dinghy.

Her sister, Lana Wood, has spoken out against this theory though, saying that Natalie was always afraid of open water and that she would have never tried to leave the boat alone. According to the New York Times , Lana once said, "Natalie would not go anywhere not fully made-up, wearing something terrific. She certainly would not get into a dinghy in her nightgown by herself. She would get dressed, put on full makeup and have Dennis Davern take her ashore to stay in a motel on Catalina, which is exactly what she did the night before, when she wanted to leave."

Christopher Walken has always maintained that he doesnt know how Natalie ended up in the water.

There have been very few times where the actor has commented on the case, but he has always alleged that he doesn't know exactly what happened that night. "I dont know what happened," he told People Magazine in 1986. "She slipped and fell in the water. I was in bed then. It was a terrible thing. Look, were in a conversation I wont have. Its a f*cking bore."

In another interview, Christopher said that Natalie went to bed before everyone else that night. "What happened that night only she knows, because she was alone," he told Playboy Magazine, according to The Hollywood Reporter . "She had gone to bed before us, and her room was at the back. A dinghy was bouncing against the side of the boat, and I think she went out to move it. There was a ski ramp that was partially in the water. It was slipperyI had walked on it myself. She had told me she couldnt swim; in fact, they had to cut a swimming scene from [Brainstorm]. She was probably half asleep, and she was wearing a coat."

In 2011, when the investigation into Natalie's death was reopened, Christopher hired a lawyer and cooperated with the investigation, though he has never actually been considered a suspect.

Multiple arguments allegedly happened the night of Natalies death.

In 2011, Captain Davern admitted that he had originally lied to authorities about what happened the night of Natalie's death, and instead alleged that a fight between Natalie and Robert may have led to her untimely death, per The Hollywood Reporter .

In his 2008 memoir, Pieces of My Heart: A Life , Robert acknowledged that he and Christopher also had an argument that night, according to The Hollywood Reporter. He wrote that Christopher went to bed, while he stayed awake. When Robert did go to bed, he noticed that Natalie and a dinghy attached to the yacht were missing.

In 2018, Davern accused Robert again in a book he co-wrote with Marti Rulli called Goodbye Natalie, Goodbye Splendour . He even alleged that Robert actually pushed Natalie to her death in the book, though Robert has always denied any kind of wrongdoing.

In 2018, authorities declared Robert a person of interest in the case surrounding Natalies death.

A Los Angeles County sheriff's investigator said he believes that Robert hasn't been completely forthcoming with all the details surrounding that night. ""I haven't seen him tell the details that match all the other witnesses in this case," said Lt. John Corina in an interview with CBS News' 48 Hours . "I think he's constantly changed his story a little bit. And his version of events just don't add up."

Robert has stated that Natalie wasn't there when he went to bed, and that she must have slipped and fell leading to her death. But Robert does open up more about that night's events in his stepdaughter's documentary. He says that Natalie and Christopher had been discussing whether she would quit acting to take care of her family, and Christopher urged her to keep acting, according to The Independent . Robert admits this made him mad, causing him to smash a wine bottle and ask the actor to mind his business.

Natalies daughter, Natasha, has always defended Robert against claims of wrongdoing.

According to the Daily Mail , in an excerpt from her book, More Than Love: An Intimate Portrait of My Mother, Natalie Wood , Natasha speaks out against the allegations against her father writing, "I focus on the things I do knowMy father would never have harmed my mother or failed to save her if he knew she was in danger."

In Natalie Wood: What Remains Behind, Natasha also expresses dissatisfaction with all those who think Robert caused Natalie's death. "You would have given your life for my mom," she tells him.

Natalie Wood: What Remains Behind premieres on HBO on May 5 at 9:00 p.m ET.