On Feb. 13, 2013, an employee at the Cecil Hotel in Los Angeles was sent to the roof of the building to investigate guests’ complaints about the hotel’s black water supply. When he opened the lid to one of the water tanks, the employee was faced with the decaying body of Elisa Lam.

To this day, it is unclear how Lam ended up in the water tower. The facts of this case point to many possibilities, but these leads  have gotten police nowhere once they were further investigated.

Lam was reported missing by her parents weeks before her body was found. Police searched the hotel thoroughly and found no traces of her on the roof or of perpetrators in her room. They searched the local area, but found no leads. Investigators then released video footage of Lam in the hotel elevator, the last place she was seen alive.

The video became popular on the internet as many called it disturbing. It was shot from the back corner of the elevator car with an overview of the car and the hallway. Lam is seen entering and exiting the car up to 5 times, apparently speaking to someone right in front of her and flailing her arms.

She rapidly pushes the buttons on the elevator’s control panel, some more than once. Periodically, she presses herself up against back corner of the car, where she cannot be seen in the footage. Finally, she rushes out of the elevator. No other person appears and the door never closed in the two minute video.

Many specialists, along with the public, offered their own theories of Lam’s strange behavior. Jack Brown, a body language specialist, concluded that her behavior may be the cause of a party drug, presumably ecstasy, in his published online analysis of the video.

Others suggest that she may have had a psychological episode. This theory was greatly supported once it was made known that Lam suffered from bipolar disorder and depression, for which she was on medication.

Once her body was found, an autopsy determined the cause of death to be accidental drowning. Rape and finger nail kits were done. There were no traces of physical trauma, rape, or conventional suicide attempts.

Given Lam’s mental health, investigators considered that she may have intentionally drowned herself. The question remained, though, as to how Lam got to the roof and into the tank. LAPD Sgt. Rudy Lopez confirmed that the doors to the roof are locked at all times and only accessible to employees with a passcode. She may have been able to reach the roof by a series of fire escapes, but how would Lam know which to use and that they would lead to the roof at all? Even with this knowledge, it is unlikely that Lam could have opened the heavy top of the water tower alone, and impossible for her to close it after she was in the tank.

After the autopsy was released, the story of Lam’s death went viral. The mysterious death was linked to the horror movie Death Water, in which the victim is found rotting in a hotel water tower. This led investigators to believe that Lam was murdered by a copycat, but no evidence was found.

The popularity of the case drew familiar attention to the Cecil Hotel, which has been linked to the infamous Black Dahlia murder of Elizabeth Short, who was last seen there. The Pigeon Lady of Pershing Square, Goldie Osgood, was raped and killed in her room there, and two serial killers lived at the Cecil while active. Additionally, five people have committed suicide by jumping out of the hotel’s windows. Elisa Lam is just another name on the list of the hotel’s tragic deaths.