Natalie Montgomery White, a friend of Vincel’s for over 20 years, tells PEOPLE her friend “had a huge heart. She always wanted to help the underdogs. She just took people in. She had so much empathy.”
Although several friends said Vincel had been having personal issues in recent years, they say she always tried to put others before herself.
“She was the most giving person in the world,” White tells PEOPLE.
On Monday, Vincel had traveled from her Springfield home to Zion, Illinois, to receive radiation treatment at the Cancer Treatment Centers of America, according to friends.
At about 9:30 p.m., while she and another patient were waiting for a shuttle at one of the center’s living quarters, an unknown man attacked her, police say. She suffered from severe head trauma and died later that night at a local hospital, police say. Police will not release any additional information, citing an ongoing investigation.
Authorities have not made an identification on the suspect, who according to an eye witness was male, black and wearing dark clothing, a Zion police department spokesperson tells PEOPLE.
Vincel, who had survived chemotherapy and a double mastectomy, planned to stay at the center for a few weeks, White tells PEOPLE.
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“She played it down – she didn’t want anybody’s pity,” White says. “She just kept a positive outlook on everything.”
White, like many of Vincel’s friends, tells PEOPLE she wishes she could confront her friend’s killer.
“She was already fighting for her life,” White says. “Why would you take that away? Why would you do something like this?”
Vincel worked from home as a hair stylist and devoted her time to her friends and two pets: a cat named Pookie and a lizard named Vinnie.
Vincel, originally from St. Louis, attended Drury University in Springfield. Matt Pylant, a friend who attended Drury with Vincel, tells PEOPLE Vincel was “a kind person” and “a free spirit” who accepted him when others ostracized him for being gay.
Pylant wrote on his Facebook page, “Shannon Vincel was my BFF my freshman year of college. When I was ostracized for being gay, Shannon gave everyone the middle finger…. I hope she knows how much she meant to me.”
Vincel planned on taking a cruise after her cancer treatment, friends say.
On Tuesday 150 people attended Vincel’s funeral.
“I write to her on Facebook like she’s still here because I think of her constantly and I just miss her,” White tells PEOPLE. “I feel her [presence] every day.”