Many said they considered Fero's a second home and bar owner Young Fero a second mother.
"This was a place where we all gathered and we all were a family," Jolene Frazzini. "We'll miss her."
Frazzino worked for Fero on and off for more than two decades.
"She would put on her roller skates and she would waitress around the bar in roller skates," Frazzini said.
"She was a cook, bartender, everything," said Fero's brother Tae Moon, and a 20-year bar employee who opened the establishment every morning.
Moon says lately, business was slow and Fero had to borrow money from people, though he couldn't say how much or from whom.
Chris Brady was in the bar playing poker just two hours before the murders.
Brady knew Fero was having financial problems, and would jokingly ask him to buy the bar.
"She just says she needs money; she's out of money," Brady said.
But her debts didn't stop Fero from feeding homeless people who came to her bar, or serving customers who didn't have enough money to cover their tabs.
"She says pay me when you can. And she does that for many people," Brady said.
Brady says the bar drew a mixed crowd.
"Young [Fero] didn't really know about all this but occasionally there were some drug deals and stuff like that going on in there," Brady said.
Brandon Landa, a regular customer for 4 years, says he loved Fero like family, and worried for her safety.
"The drugs going in and out of this bar in this area were quite prevalent," Landa said. "I think that she attracted the dangerous crowd, and in the end this is what happened."
Related Story: Denver Police Department: 5 killed before bar fire, arson suspected
It was around last call, sometime before 1:45 a.m., when someone killed Fero and 4 others before setting the bar on fire.
The fire department was first called out to the scene at 1:47 a.m. and the fire was declared under control around 2:22 a.m.
Denver Police Commander Ron Saunier said detectives believe the victims were killed before the fire started. Saunier also said there were obvious signs of trauma to the victims' bodies but would not elaborate.
The dead include Kelly Fallon, who was out celebrating her new job. Tereasa Beesley, who Frazzino says liked to stop in from time to time.
Daria Pohl and Ross Richter also died.
"The business had obviously been set on fire or arson. I'm guessing to mask the homicide that occurred inside at this point," Denver Police Commander Ron Saunier said.
The coroner listed the manner of death as homicide, but did not specify a cause.
Moon says police told him his sister was shot and burned in the fire.
"It's even worse when you know how good and nice the person was. It's horrible. It's horrible," Landa said.
Those who loved Fero continue to gather at her bar, now sitting empty and quiet for the first time in nearly three decades.
What was once a second home for many is now a shrine.
"I love you Young. I'm going to miss you so much. It should have been me. It should have been me before you," Frazzini said as she fought back tears.
Fero's daughter is scheduled to arrive from the east coast Thursday.
Denver police are looking at all possibilities.
"I would tell you one death, one homicide is certainly a concern of mine, obviously multiplied by the death of five individuals potentially being murdered at one time at one location; it's very alarming," Denver Police Chief Robert White said. "That's why it's so important we investigate it to the fullest and use the eyes and ears of anyone who might have saw or heard anything."
A check of police records shows no previous problems at the bar.
Crime Stoppers is looking for any information in this case.
You may be eligible for a reward of up to $2,000 and you can remain anonymous.
If you have a tip, call 720-913-STOP (7867).
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