Police were called to an address at the EQ Tower on A'Beckett Street about 5.15am Saturday following reports of a woman suffering serious injuries. Paramedics attended but the victim died at the scene.
One of EQ's residents, Sean, said this was a growing problem in the tower.
"This is a tragedy that sadly has been building and building over the last few months," he said.
"What we're seeing increasingly is these parties of youths getting out of control.
"They seem to come and go at short notice. Many of them are obviously intoxicated or on other substances.
"As residents, we feel intimidated that we're unable to ask them to keep the noise down."
Mr Hansen said Ms Chol was part of a group who had rented a short term stay apartment in the building. During the course of the night, a "second group" arrived at the address on the 56th floor, and "a dispute of some nature occurred resulting in the victim being assaulted".
"A number of persons have immediately left that party," Mr Hansen said.
"Police arrived to what was a fairly chaotic scene."
One neighbour, who spoke on the condition of anonymity, told reporters she heard "horrendous screaming" coming from the building in the early hours of Saturday morning.
"They were shouting and screaming and the girl's scream was incredibly loud … just screeching," she said.
"Normally I would call the police but they went off down the road.
"But it's not unusual coming from this building.
"So much goes on in the building in the middle of the night with people drunk."
Police have expressed confidence in finding the attacker responsible for Ms Chol's death.
"My understanding is this wasn't a random attack," Mr Hansen said.
"There's no sign of forced entry but we're trying to clarify what brought [the second group] there."
A family friend told the Herald Sun Ms Chol was "a very quiet person".
" … She kept her family together, she was the eldest sibling," the friend said. "She's not known for causing trouble, she doesn't rent hotels or go to parties, this was a one-off."
On social media, friends paid tribute to "a beautiful soul".
"Never thought Friday would be my last time on earth seeing you," Shushu Kishak wrote on Facebook.
"You were such a beautiful soul & didn't deserve any of this … forever remembering the memories we had.
"RIP my beautiful princess I love you."
At least 12 people are assisting the Homicide squad with inquiries but the alleged offender was not believed to be among them, police said. It's not yet clear if the two groups were previously known to each other. Mr Hansen said the only known link so far was that both groups were of "African-Australian heritage" and all members aged around 19-20 years old.
About a quarter of the EQ Tower's 633 apartments are short-term stays, according to Melbourne Real Estate which manages rentals in the A'Beckett St address.
The Financial Review reported that EQ has been swamped by Airbnb, which along with Booking.com and Expedia lists dozens of rooms owned by investors in the tower.
An Airbnb style short term rental was allegedly trashed by youths in the Melbourne suburb of Footscray in May, as was a Werribee house last December.
Another resident said that at the beginning of the night he saw a few girls in the EQ Tower lobby and a group of young men "running and yelling" outside around 4am or 5am.
CCTV footage from the apartment building is currently being reviewed by authorities as police seek to locate the second group.
Nine News has reported that several nearby residents heard an argument between a man and woman around 2am in Anthony Street, close to the apartment block where the woman was found.
The 65-storey EQ Tower is popular as a short term stay and rents rooms starting from approximately $125 per night.
Outside the building, forensic investigators this morning appeared focused on a green Honda parked on the street and sifted through a rubbish bin where they were seen retrieving a pair of jeans.
A grieving young man approached by media outside the tower asked a cameraman to stop filming, The Age reported.
"My friend just died," the man aged in his late teens or early 20s said.
Police said the victim's family has been notified of her death.
"We've put support around the family … we are reaching out not only to the family but the extended community of the victim," Mr Hansen said.
The area was earlier cordoned off but traffic is now moving freely through A'Beckett Street. Nearby, Anthony Street remains closed as police scour the area for evidence.
