On 28 January 2013, Canadian student Elisa Lam checked into the Cecil Hotel in downtown Los Angeles. Three days later, the 21-year-old – who was travelling solo – was reported missing. After three weeks, her body was discovered in a water tank on the roof of the hotel.

These are the true facts about the death of Lam, which was confirmed as an accidental drowning by the LA coroner’s office. But the case left many unanswered questions. When footage of her last known moments – behaving erratically in the hotel’s lift – came to light later, some began to believe that this was more than just a tragic mistake

The case is said to be the inspiration for Ryan Murphy’s American Horror Story: Hotel, and for a series of How To Get Away With Murder, but now it’s being re-examined in a four-part documentary series on Netflix. It questions the apparent inconsistencies within the case, and explores theories which have been further pushed by a group of “internet sleuthers”, who have taken it upon themselves to reveal what they believe to be a cover up. So what exactly is the case about, and how much of the story can we trust?

The notorious Cecil Hotel, in downtown LA

The hotel

Even before Lam’s death, the Cecil Hotel wasn’t exactly top of anyone’s TripAdvisor list. Set just metres away from the deprived Skid Row area of LA, it was something of a favourite for the city’s serial killers, with Jack Unterwegger and Richard Ramirez, aka the Night Crawler, both staying there while committing their crimes.

It’s also experienced more than its fair share of violence, which led to it being dubbed ‘Hotel Death’ for the number of crimes that have been committed there (not that they put that on the letterhead). All of which only added to the mystery of Lam’s death. Was she another victim?

Elisa Lam’s disappearance

Lam called her parents to check in every day of her break, but on 31 January, the day she was due to check out of the hotel and leave for Santa Cruz, she was uncontactable. Her parents called the police.

Police and firefighters search the roof of the Cecil Hotel

The LAPD did a functional check of the hotel with sniffer dogs, including Lam’s room and the rooftop, where the water tanks were based. But they failed to find anything. According to the LA Times, Sergeant Rudy Lopez later admitted: “We didn’t search every room… we could only do that if we had probable cause to believe a crime had been committed.”

By 15 February, Lam was still missing and there were no leads, so the police released the last known footage of Lam in Hotel Cecil’s lift. The video quickly went viral online, due to the strangeness of Lam’s behaviour.

In the CCTV footage, she’s shown pressing all the buttons on the middle panel of the lift, which held the doors open, then she jumps nervously in and out of the lift. At one point, she looks like she’s hiding from someone, then at another point, she jumps back out into the corridor, gesticulating and apparently talking to someone else. The question then arose: who was she talking to, and did they have anything to do with her disappearance?

The documentary’s director, Joe Berlinger, told The Independent: “[The footage] is strange and seemingly inexplicable. The enigmatic nature of the video is really what drew many people around the world, including me, to become passionate about the case and want to solve its mysteries.”

The video had millions of hits within days, and web detectives began to speculate about what different aspects might mean. Several people picked up on the idea that she was trying to escape somebody in the corridor, but the lift doors were being held by them outside. Others suggested her erratic behaviour could be the result of drugs, while some dreamed up wilder conspiracy theories: the time stamp had been erased and the video manipulated as part of a cover up between the hotel management and LA police; it was the Illuminati; it was a paranormal spirit; it was the military in an invisibility cloak.

Lead investigator Tim Marcia, of the LAPD

The tragic discovery

Guests staying in the hotel at that time began to complain about black water coming out of their taps that also tasted funny. When a hotel caretaker checked the water tanks on the hotel rooftop on 19 February, he made a stomach-turning discovery: Lam’s body was decomposing in one of the tanks.

The autopsy revealed that she was naked, but with no sign of sexual assault, and had died by drowning. But questions remained: how did she make it up to the rooftop? Why did she go into the water tanks? Was she trying to escape from somebody? And why, as one of the policemen first claimed, was the heavy cement roof placed back upon the tank lid if she herself was inside?

All these questions fuelled even more speculation. But it later transpired that Lam was diagnosed as bipolar and suffering with depression, both of which she was on medication for. The autopsy revealed trace amounts of her prescribed drugs, which suggested that she had stopped taking them, potentially triggering a psychotic episode. In her confused state, she may well have climbed into the water tanks.

The caretaker later confirmed that the lid of the tank had been off when he found it, and the coroner suggested that while treading water in the tank, Lam may have taken off her clothes to lessen her weight, or it might have been a side effect of hypothermia.

As is quite often the result of these cases, the death of Elisa Lam appears to have just been a tragic accident. However, just like in The Staircase and Making A Murderer, the documentary looks set to reopen online debate about what might have happened once again.