Breast Cancer Patient Beaten to Death While Waiting for Radiation Treatment

(INSIDE EDITION) A cancer patient was brutally beaten to death last week by an unknown suspect while waiting for a shuttle to take her to treatment outside an Illinois hospital.

Shannon Vincel had already undergone a double mastectomy in her brave battle to beat breast cancer when she traveled from Springfield, Missouri, to Illinois to undergo radiation therapy.

While outside the Cancer Treatment Centers of America in Zion, the 46-year-old was hit in the head from behind with an unknown object.

She died the next day.

Vincel's heartbroken family says the attack was not a robbery. Her loved ones have been left dumbstruck by the assailant's apparently random desire to cause harm.

A witness described the attacker to police as black and wearing dark clothing.

He allegedly approached Vincel and the witness on the sidewalk while the two were seated outside the hospital. The offender then struck Vincel and fled.

In a bid to bring Vincel justice, the Cancer Treatment Centers of America has pledged $25,000 for information leading to the arrest and conviction of her killer.

In her obituary, Vincel's family described her as a beloved friend and animal lover.

"Shannon was a friend to many and will be greatly missed by her beloved pets Tookie and Vinnie. She will be remembered for her friendliness and happy smiling face," it reads.

Funeral services are planned for Tuesday.