Elisa was last seen acting strangely in a hotel lift. Then her body was found in an unexpected place.

This post deals with mental health and might be triggering for some readers.

It was a Tuesday morning when the complaints started trickling into the front desk of Los Angeles' Cecil Hotel.

The complaints were about the site's water, which was coming out of the taps brown and had a strange "metallic taste."

So, on February 19, 2013, maintenance worker Santiago Lopez took the lift to the 15th floor of the once grand building, built during the Art Deco period.

The Cecil was built in 1924. Image: Getty.

From the 15th floor, Lopez took the stairs to the roof. He disabled the access alarm, walked across to a platform, and then climbed a ladder to the top of the downtown building's three metre-tall water tanks.

He noticed one of the hatches was open. So, he peered in.

Inside the tank was the body of a woman face up in the water, naked, with her clothes floating beside her.

It was a guest who had vanished less than three weeks earlier: 21-year-old Canadian tourist, Elisa Lam.

Listen to True Crime Conversations cover the Cecil Hotel case. Post continues below.

The disappearance of Elisa Lam.

The discovery would set off an investigation and an internet tidal wave that left employees dumbfounded — and millions around the world intrigued.

Elisa's death has haunted Amy Price, former manager of the Cecil Hotel, for more than 10 years. The hotel already had a shadowy reputation by the time Price started working there.

Elisa Lam. Image: LAPD.

The venue, located on LA's notorious "Skid Row", was rumoured to have once provided refuge to serial killers Richard Ramirez "The Night Stalker", and Jack Unterweger.

Originally built for the business traveller in 1924, the hotel became the site of multiple murders, suicides and overdoses.

"I estimate, probably over 80 people died while I worked there," Amy told Mamamia's True Crime Conversation podcast, explaining the area was a rough one.

Elisa's death would become the Cecil Hotel's most high profile death, and Amy remembers the exact moment she first heard the Canadian tourist's name.

"I was aware of Elisa Lam while she was staying at the hotel, because she was disruptive," Amy said.

"She stayed in a room with eight or seven other women. We relocated her to her own room, and then she went missing."

Originally, Elisa's disappearance didn't raise any red flags for Amy. It wasn't rare for guests to forget to check out, to leave their property.

Then police turned up. Elisa's parents contacted investigators and reported her missing when they couldn't reach her.

"As the days went on and she was still missing, I mean, it was alarming," Amy said.

"I never felt that she would be found at the hotel."

Photos showing Elisa Lam set at a street memorial across the Cecil Hotel in Los Angeles Thursday, Feb. 21, 2013. Image: AP via AAP.

Amy said she has grappled to make sense of Elisa's death in the years since.

"It affected us all so much and in so many different ways, but there was a lot of trauma, you know, with our staff," Amy said.

"I never, ever want to forget about the loss of life. A life was lost. A young woman died, and the way she died is horrific, but life was lost. Someone lost a daughter, you know."

What happened to Elisa Lam?

The University of British Columbia student was on a solo holiday, bound for Santa Cruz, California, when she checked into the Cecil Hotel on January 28, 2013.

The last time she used her phone was on January 31 and her concerned family reported her missing on February 8.

Speculation about Elisa's disappearance went global after Los Angeles Police Department released CCTV footage of her last-known movements.

The clip, which has been viewed more than 28 million times on YouTube, lasts four minutes and captured Elisa entering the lift at the Cecil Hotel on February 1.

Watch: The last known footage of Elisa Lam. Post continues below.

She is wearing the same clothes that were found alongside her body in the water tank and is seen acting erratically.

She presses buttons for several floors, then hides in the corner. She ducks in and out of the lift, glances in several directions and when she moves into the hallway the final time, she makes strange, sweeping gestures with her hands and wrings her fingers.

No-one else is captured in the frame.

"What that elevator footage means to me is somebody that is very paranoid. Somebody that yes, she might have been afraid, but mostly paranoid. And if she was looking for a hiding spot, she found one," Amy said.

The official cause of Elisa's death was determined to be an accidental drowning. According to an autopsy report, there were no obvious traces of alcohol or illicit drugs in her system, and she had no history of suicidal ideation and had never attempted to take her own life.

How and why she ended up in the water tank, though, remains unknown. The LAPD investigation proved inconclusive.

The door to the roof was alarmed, but no employees recalled it being activated in the time between her disappearance and the discovery of her body. It's been speculated that she may have accessed the roof through a window that led onto one of the building's three fire escape stairways — each is clearly marked for emergency use only.

The case remains popular with internet sleuths, who have pored over court documents, coronial findings and the bizarre CCTV footage in the search for an explanation.

The most persistent theory they've leveraged is related to her mental health. Elisa lived with depression and bipolar disorder, for which she took several prescribed medications. Bipolar disorder was listed as a contributing factor in the autopsy report, and some have speculated that she may have been in the grips of a manic episode at the time of her death.

Though mania presents in a variety of ways, extreme episodes can trigger psychosis and hallucinations.

More far-fetched speculation has pointed to similarities between Elisa's death and the 2005 supernatural horror film Dark Water.

The movie, which stars Jennifer Connelly, follows a family who moves into an apartment building that has issues with plumbing: the taps run black, dark water drips from the ceiling. They later discover a neighbour's young daughter died in the rooftop water tank. In the final scenes, the family's own daughter shares the building's lift with a ghost.

In 2015, Elisa's family filed a negligence suit against the Cecil Hotel, alleging that the water tank should have been better secured to prevent such an accident occurring. The suit was dismissed.

They are no closer to finding precisely what happened.

The mystery of Elisa's death also became the subject of a Netflix documentary series, Crime Scene: The Vanishing at the Cecil Hotel.

If you or anyone you know needs to speak with an expert, please contact your GP or in Australia, contact Lifeline (13 11 14), Kids Helpline (1800 55 1800) or Beyond Blue (1300 22 4636), all of which provide trained counsellors you can talk with 24/7.

If you have been bereaved or impacted by suicide loss at any stage in your life, StandBy is a free service you can access on 1300 727 247.

This post was originally published on September 3, 2020, and has been updated with new information.

Feature image: LAPD.