Campbell was transported to Harborview Medical Center and was listed in critical condition Jan. 8.
Courtney Campbell's friends said she had recently improved under treatment in the burn unit of Harborview Medical Center.
"There was hope," said Campbell's close friend Ben Scott. "The nurses were optimistic. Her boyfriend said she looked better than she had since the accident happened. We were all making plans," he said.
Campbell's condition took a turn for the worse on Monday afternoon.
"I got a phone call, and it just completely crushed my world," Scott said.
Now Scott and his friends are promoting a concert and a GoFundMe page to raise money for Campbell's two young daughters.
"The girls' lives have just drastically changed," Scott said. "They lost a mother. I can't even begin in my head (to imagine) what those girls are going through."
The benefit concert will be Saturday, Jan. 16 at Tony V's Garage, a concert venue.
The fire -- which is still under investigation -- involved a propane tank inside the stand, according to investigators.
Campbell, despite being badly burned, was able to walk to an arriving ambulance.
As new spread of Campbell's death, friends left well wishes and flowers at the barista stand Campbell owned, which is covered in tarps.
"She was not just a business owner, she was just a great person," said Laurie Pearson while she left a bouquet at the stand.
"She would do anything for anybody. If you ask her for anything, she would help you out, she was so generous," said Pearson.
Fire investigators are continuing into the cause of fire.
KIRO 7 News video showed the charred espresso stand on Everett Mall Way and Fourth Avenue. People who were nearby also shot cellphone video and said they heard explosions leading up to and during the fire.
"After reviewing security video, we believe a propane tank stored inside the coffee stand contributed to the fire,” said Everett Assistant Fire Marshal Eric Hicks.
As for the explosions sounds, he said it may be the cause of the fire but could also be the tires of the car or aerosol cans popping in the heat.
The owner of the Shell gas station next to the stand said his cameras likely caught the beginning of the fire on camera, but he could not view the video on Thursday evening because of power outage issues caused by the fire.
“It was decimated,” Campbell's best friend Ben Scott said. "Courtney is one of those people who basically walked out of a cartoon and into real life. She's got that bubbly, amazing personality.”
He says the mother of two young girls had been working for years in order to work for herself.
"That's been a dream of hers, pretty much her entire life, to have her own coffee stand, so that was a huge deal," Scott said.
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