A Canadian student named Elisa Lam from the University of British Columbia in Vancouver was found lying face up in a water tank above the infamous Cecil Hotel in Los Angeles on Feb. 19, 2013. She died at the age 21.

Lam began her trek around California at the beginning of 2013, taking photos at the San Diego Zoo and visiting other areas prior to her stay at the Cecil Hotel.

The Cecil Hotel is infamous for having several murders and suicides prior to Lam’s death, as well as being a ground for illegal activities. Since it’s inception in 1924, there have been 15 technical deaths on the premises. The famous “Black Dahlia” Elizabeth Short was spotted at the hotel days before her murder.

January 31 was her check out date at the hotel, but the date was not met by Lam. Her parents had been worried about her whereabouts as they had not heard from her in a while. Her parents contacted the Los Angeles Police Department and the search for Lam had started. The hotel was searched, but nothing about Lam could be found.

Days after, the chilling surveillence footage of one of the hotel’s elevators was released by the police. The two and a half minute video shows Lam walking into the elevator and pressing all of the buttons. She then keeps stepping in and out of the elevator, or poking her head out as if she was supposed to be hiding from someone. She eventually leaves the elevator, and the last few moments of the low quality video show her waving her hands around in various gestures as if she were talking to someone, but Lam was the only one seen on the video.

The body was later found due to complaints by residents about foul tasting water and water pressure problems, leading Santiago Lopez, a maintenance worker at the time, to check on the water tanks at the top of the building. Her body was found naked, with her clothes floating beside her body in the tank.

“In 22 years plus of doing this job as a news reporter, this is one of those cases that kinda sticks with me because we know the who, what, when, where. But the why is always the question,” said Lolita Lopez, a NBC reporter who covered Lam’s case.

The autopsy took around four months, and ended up ruling the death as an accidental drowing.

Lam was previously diagnosed with an extreme case of bipolar disorder and depression and was recieving treatment. Her parents said she had no prior suicide attempts, though her parents were known to not disclose her history of mental illness. It was discovered she had written blog posts to cope which detailed her journey with her bipolar disorder and depression.

“She was outgoing, very lively, very friendly,” said Katie Orphan, manager at a nearby bookstore, who had seen Lam before her death when she went to buy gifts for her family back home.

The case went viral, and the internet had many theories about the mysterious circumstances of her death. To this day, no one knows how Lam ended up in the water tank at the top of the hotel.