The tourist’s nude body was discovered in the hotel’s rooftop water tank on Feb. 19, 2013 

The mysterious death of Elisa Lam has confused authorities for more than 8 years.

In January 2013, she traveled to Los Angeles from her hometown of Vancouver, British Columbia, for a week of sightseeing and adventure. But things soon took a mysterious — and deadly — turn. After checking into the Cecil Hotel, the 21-year-old tourist vanished without a trace.

For weeks, her loved ones searched for her. Then, on February 19, 2013, a hotel maintenance worker made a grisly discovery when he found Lam’s body inside a water tank on the roof of the hotel.

How Lam died became a subject of intense speculation. Lam’s death, and the other mysteries surrounding the Cecil Hotel, are the focus of an episode of a new Netflix documentary series.

Crime Scene: The Vanishing at the Cecil Hotel was released on Feb. 10. Here are 3 things to know about the mysterious case.

1. The Hotel Has Been the Scene of Other Mysterious Deaths

Lam is the last known casualty of the Cecil Hotel, which was built in the 1920s near L.A.’s downtown Skid Row. It inspired a season of American Horror Story starring Lady Gaga.

Numerous murders and suicides allegedly occurred there, and it was, for a short period of time, the home of serial killer Richard Ramirez, also known as the Night Stalker.

the Cecil Hotel. Nick Ut/AP/Shutterstock

2. Lam’s Cause of Death Was Drowning

Four months after Lam’s death, the L.A. coroner’s office determined that there was no evidence of physical trauma. The manner of death was classified as an accidental drowning and the case was closed.

But the mystery remains: How did Lam get onto the locked roof and into the water tank? And why would she have voluntarily gone to the tank in the first place?

3. Lam Was Seen Acting Strangely Before Her Death

Elevator surveillance video released by police showed some of Lam’s odd behavior hours before her disappearance. The video shows her, clad in a red hoodie, inside an elevator pushing buttons for multiple floors, peering out of the opened elevator and cautiously stepping out while waving her arms. It’s unclear what — or who — she may have seen.

Crime Scene: The Vanishing at the Cecil Hotel is available on Netflix.