The investigation into the death of actress Natalie Wood has been reopened, announced the L.A. Sheriff's Department late Thursday, citing new information. The West Side Story star drowned 30 years ago, on Nov. 29, 1981, off the coast of California during a weekend of yachting with her husband, Robert Wagner, and friend Christopher Walken. Though her death was originally ruled an accidental drowning, questions surrounding the incident have lingered over the last three decades. Here, a guide to the case and why it's being reopened:

What was Natalie Wood most famous for?
Playing Maria in the film version of the musical West Side Story, but her career was flourishing long before that. As a 9-year-old child star, she played the lead in 1947's Miracle on 34th Street. Before the age of 25, she received three Academy Award nominations, for her roles in Rebel Without a Cause, Splendor in the Grass, and Love with the Proper Stranger. Wood was only 43 at the time of her death.

How did she die?
After a night of drinking on a yacht with Wagner and Walken, with whom she was filming the sci-fi movie Brainstorm. Wood's body — dressed in a night gown, long socks, and a down jacket — was found floating in a Catalina Island cove, about a mile from the yacht. According to Wagner, he and Walken had gotten into an argument. After Wagner broke a wine bottle, Wood stormed off in embarrassment. When he went to go check on her, she was gone. He believes that Wood was so angry she decided to take the yacht's dinghy to shore. The dinghy was discovered about a mile from the yacht, and about a mile from where her body was found, says CNN. The autopsy report says Wood may have had seven or eight glasses of wine the night of her death. Fingernail scratches were found on the side of the dinghy, indicating that Wood may have tried to climb back in.

What is the mystery?
In 2009, Wood's family went on record that they doubted Wagner's dinghy story. "My sister was not a swimmer and did not know how to swim," Lana Wood tells CNN. "She would never go to another boat or to shore dressed in a nightgown and socks." Indeed, Wood once revealed in a televised interview that "her greatest fear was of dark seawater." Marti Rulli, the author of a book about Wood's death, disputes the coroner's report's suggestion that Wood's down jacket became water logged and weighed her down in the water. Actually, Rulli tells TMZ, forensic tests show that the jacket would have served as a floating life preserver. According to the autopsy report, Wood's body was covered in two dozen bruises when it was found.

Why is the case being reopened now?
According to the Los Angeles Times, L.A. county detectives want to explore recent claims made by the yacht's captain, Dennis Davern, who doubts that Wood took the dinghy to shore, and says she was unbruised the last time he saw her on board. Davern also contradicts Wagner's report, saying that Wagner followed Wood to their cabin after he broke the wine bottle, and proceeded to argue with her. After she went missing, Davern says that Wagner waited four hours to call the Coast Guard, and told him not to turn on a searchlight to see if Wood was in the water. He tells CNN that listening to Wagner "was a mistake that I made."

What now?
Appearing on the Today show Friday morning, Davern said that he initially lied to authorities about important details relating to Woods' death, and that he holds Wagner "responsible" for stalling search-and-rescue efforts. But in a press conference, the L.A. County Sheriff's Department said that Wagner is still not a suspect in Wood's death. Investigators say they will look into "credible and substantial [new] information" from multiple sources related to the drowning. Meanwhile, Davern will be reinterviewed.

Sources: Entertainment Weekly (2), KTLA, iMDB, International Business Times, LA Times, Reuters, Slate, TMZ