The body of a woman recovered Tuesday from a water tank on the roof of a downtown Los Angeles hotel is that of 21-year-old Elisa Lam, a Canadian tourist who stayed at the hotel before she disappeared several weeks ago, police officials said late Tuesday.

At about 10:15 a.m., police were called to the Cecil Hotel. The Los Angeles Fire Department also responded. The body was removed at about 4:30 p.m. after an urban search and rescue team worked to free the remains while trying to maintain evidence, authorities on scene said.

Hotel guests had reported that the water pressure in the building was low, prompting a maintenance worker to visit tanks on the roof, where the body was found, according to Los Angeles Police Department Officer Sara Fayden.

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Officials were gathered on the hotel's roof at midday, and multiple emergency vehicles were parked in front of the building, including a sedan from the county coroner's officer.

LAPD homicide detectives had been investigating the disappearance of Lam, a Vancouver, B.C., resident who had stayed at the hotel during a visit to Southern California last month.

Surveillance video from the hotel had shown Lam in the hotel's elevator on Feb. 1. She seemed to push multiple buttons in the elevator, then stepped in and out and appeared to hide in a corner in what authorities described as "abnormal" behavior.

Watch: Surveillance Video

The surveillance video is the last known image of Lam, whose parents said she had called them every day until she disappeared, according to police.

Lam had stayed at the Cecil Hotel during a visit to LA that began Jan. 26, but when it came time for her to check out, she could not be found. She was last seen Jan. 31.

LAPD via Reuters

Elisa Lam of Vancouver, British Columbia, is seen in this undated handout photo provided by the Los Angeles Police Department.

The water tank was about three-quarters full when the body was found, according the Sgt. Rudy Lopez of the LAPD. He said the tank's metal latch could be easily opened but added that access to the hotel's roof is secured with an alarm and lock.

A spokesman for the Los Angeles County Department of Public Health said the agency was investigating the four 4-foot-by-8-foot water tanks to determine whether the hotel's water supply had been contaminated.

Fire Capt. Jaime Moore said a water sample had shown "no biohazard concerns" and that the hotel's water tanks were not connected.

Longtime hotel resident Bernard Diaz reported flooding on the fourth floor at about the time Lam disappeared, saying he heard a thump so loud one night he "fell out of bed."

The building, located near Skid Row, is described on its website as a "beautiful vintage European-style hotel built in the 1920s."

The single-room-occupancy hotel has an unusual history. "Night Stalker" Richard Ramirez, who was found guilty of 14 slayings in the 1980s, lived on the 14th floor for several months in 1985. And international serial killer Jack Unterweger is suspected of murdering three prostitutes during the time he lived there in 1991. He killed himself in jail in 1994.

In 1962, a female occupant jumped out of one the hotel's windows, killing herself and a pedestrian on whom she landed.

LAPD via AP

Police search for Elisa Lam of Vancouver, British Columbia, Canada. She was visiting Los Angeles and last seen at a downtown hotel.

Homicide detectives are investigating the disappearance of Elisa Lam, a Canadian tourist who was last seen in downtown Los Angeles on Jan. 31.

Lam, 21, had been staying at the Cecil Hotel on Main Street. Surveillance video released by the Los Angeles Police Department showed her entering the hotel’s elevator and attempting to use it.

Police said Lam, who is from Vancouver, British Columbia, had been planning to go to Santa Cruz on her trip to the U.S. Police said they did not know why she had come to California, however.

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An LAPD release described Lam as 5 feet 4 inches tall, weighing about 115 pounds. She is of Chinese descent, and speaks Cantonese as well as English.

Police said she tends to use public transportation, including buses and trains.

The LAPD has asked that anyone with information about the case call homicide detectives at (213) 486-6890.

A woman visiting New York City was raped in an alleyway near a nightclub in midtown early Sunday morning, police said.

The 20-year-old woman from Australia left the club, Lavo, and got into a cab, but fought with the driver and exited the taxi after a short distance, police said.

She had just exited the taxi on East 58th Street at about 3:30 a.m. when she was grabbed from behind.

She was then dragged into an alleyway, where she was sexually assaulted, police said.

According to a law enforcement official, the woman then got into a second cab and texted a friend that she had just been raped. Police were called and met her at another location where she was headed on the west side.

Because she was so intoxicated, the official says, the woman cannot recall the exact location where she was raped.

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People who live and work in the area were surprised about the attack.

"It's a good neighborhood, it's a high-class neighborhood," said Joe Agate, a delivery person who works near the nightclub.

He noted that it's usually very quiet when he works in the early morning.

Police have released a sketch of the suspect, who's described as being in his mid- to late-30s, about 6 feet 2 inches tall and weighing 190 pounds.

Anyone with information is asked to contact Crime Stoppers at 800-577-TIPS.