2013 accidental drowning in Los Angeles
On February 19, 2013, the body of Canadian tourist Elisa Lam (born as Lam Ho-yi";" ) was recovered from a large cistern atop the Stay on Main hotel in Downtown Los Angeles, where she had been a guest. She was last seen alive on January 31 and was reported missing by her parents on February 8. Her body was discovered by a hotel maintenance worker investigating complaints of flooding and low water pressure.
Interest in Lam's disappearance increased on February 13 when the Los Angeles Police Department released security camera footage of her behaving erratically in a hotel elevator on the day she was last seen alive. The video went viral. While an autopsy performed on February 21 was inconclusive in determining the manner of Lam's death, the Los Angeles County Coroner's office subsequently ruled the death an accident with bipolar disorder being a significant contributing factor. 
Guests at the Stay on Main sued the hotel over the incident and Lam's parents filed a separate suit later that year; the latter was dismissed in 2015. Some of the early Internet interest noted what were considered to be unusual similarities between Lam's death and the 2005 horror film "Dark Water". The case has since been referenced in international popular culture and been the subject of several creative works.
Background.
Lam, the daughter of immigrants from Hong Kong, was a student at the University of British Columbia, although she was not registered at the beginning of 2013.
In mid-2010, Lam began a blog named Ether Fields on Blogspot. Over the next two years, she posted pictures of models in fashionable clothing and accounts of her life, particularly her struggle with mental illness. In a January 2012 blog post, Lam lamented that a "relapse" at the start of the current school term had forced her to drop several classes, leaving her feeling "so utterly directionless and lost." She titled her post "You're always haunted by the idea you're wasting your life" after a quotation from novelist Chuck Palahniuk. She used that quote as an epigraph for her blog. Lam worried that her transcript would look suspicious with so many withdrawals and that it would result in her being unable to continue her studies and attend graduate school.
A little over two years after Lam had started blogging, she announced she would be abandoning her blog for another she had started on Tumblr, "Nouvelle-Nouveau". Its content mostly consisted of fashion photos, quotes and a few posts in Lam's own words. The same Palahniuk quotation was used as an epigraph.
Lam had been diagnosed with bipolar disorder and depression. She had been prescribed several medications for her mental health issues: Wellbutrin, lamotrigine, quetiapine, Dexedrine Spansule, and venlafaxine. According to her family, who reportedly kept her mental illness private, Lam had no history of suicidal ideations or attempts, although one report claimed she had previously gone missing for a brief period. Lam had a history of not taking her bipolar medications and, as a result, on several occasions suffered hallucinations that would cause her to hide under her bed for refuge; she was hospitalized at least once for one of these episodes.
For her trip to California, Lam traveled alone on Amtrak and intercity buses. She visited the San Diego Zoo and posted photos taken there on social media. On January 26, she arrived in Los Angeles. After two days, she checked into the Cecil Hotel, near Downtown's Skid Row. Lam was initially assigned a shared room on the hotel's fifth floor; however, her roommates complained about what the hotel's lawyer would later describe as "certain odd behavior" and Lam was moved to a room of her own after two days. According to Amy Price, the manager of the Cecil Hotel and Stay on Main at the time of Lam's disappearance, Lam was leaving notes for her roommates that said "go home" and "go away," and would lock the door to the room and require a password for entry. A few days before her disappearance, Lam attended a live taping of "Conan" in Burbank, but was escorted off the premises by security due to disruptive behavior.
Disappearance.
Lam contacted her parents in British Columbia daily while traveling up until the day she disappeared. On January 31, 2013, the day she was scheduled to check out of the Cecil and leave for Santa Cruz, her parents did not hear from her and called the Los Angeles Police Department (LAPD); her family flew to Los Angeles to help with the search.
Hotel staff who saw Lam that day said she was alone. Outside the hotel, Katie Orphan, manager of The Last Bookstore, was the only person who recalled seeing her that day. "She was outgoing, very lively, very friendly" while getting gifts to take home to her family, Orphan told CNN. "[She was] talking about what book she was getting and whether or not what she was getting would be too heavy for her to carry around as she traveled," Orphan added.
Police searched the hotel to the extent that they legally could. They searched Lam's room and had dogs go through the building, including the rooftop, but the dogs were unsuccessful in detecting her scent. "But we didn't search every room," Sgt. Rudy Lopez said later, "we could only do that if we had probable cause" to believe a crime had been committed. On February 6, a week after Lam had last been seen, the LAPD decided more help was needed. Flyers with her image were posted in the neighborhood and online. It brought the case to the public's attention through the media.
Elevator video.
On February 13, after another week with no sign of Lam, the LAPD released a video of the last known sighting of her taken in one of the Cecil's elevators by a video surveillance camera on January 31. In approximately two and a half minutes of footage, Lam, alone, makes unusual moves and gestures. She appears to press every button on the elevator panel, peers into the hallway, then leaves the elevator at one point while its doors remain open. When the doors fail to close after she returns, she leaves; the doors close later.
The video drew worldwide interest in the case due to Lam's strange behavior, and has been extensively analyzed and discussed. It was reposted widely, including on the Chinese video-sharing site Youku, where it accumulated 3million views and 40,000comments in its first 10days. Many of the commentators found it unsettling to watch.
Several theories emerged to explain her actions. One was that Lam was trying to get the elevator car to move in order to escape from someone who was pursuing her. Others suggested that she might be under the influence of ecstasy or some other party drug, but none was detected in her body. When her bipolar disorder became known, the theory that she was having a psychotic episode also emerged.
Other viewers argued that the video had been tampered with before being made public. Besides the obscuring of the timestamp, they claimed, parts had been slowed down and nearly a minute of footage had been removed. This could have been done to protect the identity of someone who otherwise would be in the video, either related or not to the disappearance.
Discovery of body.
During the search for Lam, guests at the hotel began complaining about low water pressure. Some later claimed their water was colored black and had an unusual taste. On the morning of February 19, Santiago Lopez, a hotel maintenance worker, found Lam's body in one of four 1,000-gallon (3,785 L) tanks located on the roof providing water to guest rooms, a kitchen, and a coffee shop. Through the open hatch he saw Lam lying face-up in the water. The tank was drained and cut open since its maintenance hatch was too small to accommodate equipment needed to remove Lam's body.
On February 21, the Los Angeles coroner's office issued a finding of accidental drowning, with bipolar disorder as a significant factor.
The full coroner's report, released in June, stated that Lam's body had been found naked; clothing similar to what she was wearing in the elevator video was floating in the water, coated with a "sand-like particulate". Her watch and room key were also found with her.
Lam's body was moderately decomposed and bloated. It was mostly greenish, with some marbling evident on the abdomen and skin separation evident. There was no evidence of physical trauma, sexual assault, or suicide. Toxicology tests showed traces consistent with prescription medication found among her belongings, plus nonprescription drugs such as Sinutab and ibuprofen. A very small quantity of alcohol (about 0.02 g%) was present, but no other recreational drugs. Investigators and experts have however noted that the concentration of her prescription drugs in her system indicated that she was under-medicating or had stopped taking her medications recently.
Theories and speculation.
The investigation determined how Lam died, but did not initially offer an explanation as to how she got into the tank in the first place. Doors and stairs that access the hotel's roof are locked, with only staff having the passcodes and keys, and any attempt to force them would supposedly have triggered an alarm. The hotel's fire escape could have allowed her to bypass those security measures; her scent trail was lost near a window that connected to it. A video posted to the Internet after Lam's death showed that the hotel's roof was easily accessible via the fire escape and that two of the lids of the water tanks were open.
Apart from the question of how she got on the roof, others asked if she could have gotten into the tank by herself. All four tanks were cylinders propped up on concrete blocks; there was no fixed access to them and hotel workers had to use a ladder to look at the water. They were protected by heavy lids that would be difficult to replace from within. The hotel employee who found the body said that the lid was open at the time, removing the issue of how she could have closed the lid from inside. Police dogs that searched through the hotel for Lam, even on the roof, shortly after her disappearance was noted, did not find any trace of her.
Proponents of the theory that the elevator video shows she was under the influence of illicit drugs are not dissuaded by their absence from the toxicology screen, suggesting that they might have broken down during the period of time her body decomposed in the tank or that she might have taken rare cocktails of such drugs that a normal screen would not detect. The very low level of her prescription drugs in her system, and the number of pills left in her prescription bottle, suggested she was under-medicating or had recently stopped taking her medication for bipolar disorder, which might have led to a psychotic episode.
The autopsy report and its conclusions were also questioned based on the incomplete information. For instance, it does not say what the results of the rape kit and fingernail kit were or even if they were processed. It also records subcutaneous pooling of blood in Lam's anal area, which some observers suggested was a sign of sexual abuse; one pathologist noted it could also have resulted from bloating in the course of the body's decomposition, and her rectum was also prolapsed. The coroner's pathologists were ambivalent about their conclusion that Lam's death was accidental. 
After her death, her Tumblr blog was updated, presumably through Tumblr's Queue option that allows posts to automatically publish themselves when the user is away. Her phone was not found either with her body or in her hotel room. Whether the continued updates to her blog were facilitated by the theft of her phone, the work of a hacker, or through the Queue is not known; nor is it known whether the updates are related to her death.
Litigation.
In September 2013, Lam's parents filed a wrongful death suit, claiming the hotel failed to "inspect and seek out hazards in the hotel that presented an unreasonable risk of danger to (Lam) and other hotel guests" and seeking unspecified damages and burial costs. The hotel argued it could not have reasonably foreseen that Lam might have entered the water tanks and since it remained unknown how Lam was able to get into