By Colleen Chen, NEWS 9

OKLAHOMA CITY -- More than 100 people gathered at a southwest Oklahoma City where four people were killed in a house fire started by arson to give their condolences and show a unified fight for justice.

Officials have not released the names of the four people killed or how they died, but on Tuesday night, friends told NEWS 9 that 22-year-old Milagros Barras was one of the victims who died in Monday's blaze.

Friends put up a makeshift memorial and held a candlelight vigil outside of the home in honor of their friend who they called Millie.

Dozens stood in silence for well over an hour praying for investigators who continued to gather evidence at the house Tuesday and for the three other families affected by this tragedy. Most didn't know any of the other victims and said they weren't sure how Millie ended up a victim of the arson.

"I just hope they find this guy that did this. I don't know if it's a guy or girl. I just hope they find the person who murdered these innocent people. It was unfair for them to go this way. She was just trying to have fun," said Thelma Pinilla, vigil organizer.

Investigators believe a fifth person was at the home when the home caught fire. They are looking to figure out who that is.

Police told NEWS 9 they're waiting for the Medical Examiner to determine the exact cause of death because that could change the course of the homicide investigation.

There has been a special phone line set up specifically for tips regarding the homicides relating to the house fire. Anyone with information regarding this case should call (405) 297-1200. The new phone line will be manned, but if nobody answers, callers should leave a voicemail, as the line will be checked for messages regularly. This phone line is only for tips regarding this case. If it is an emergency, please call 911.