SPRING VALLEY, N.Y. (CBSNewYork) — A Rockland County community is in shock after the murder of a woman who recently became a grandmother.

Sandra Wilson was killed when witnesses say a man with a knife charged into the Spring Valley library and repeatedly stabbed her.

READ MORE: 16-Year-Old Killed In Double Shooting On Lower East Side, Second Victim In Hospital

Friends say she was the kind of lady who greeted everyone with a smile and was kind to every person who walked through the doors. They can’t imagine who would want to hurt her, and they can’t believe this happened in a place they assumed was so safe.

A quiet prayer and a promise were made outside Finkelstein Memorial Library on Tuesday night for a beloved friend who lost her life inside while she was on the job.

“Devastated and dismayed and in shock,” said Christine Ball, a friend and co-worker.

“I wasn’t expecting this kind of news. I’m so sad,” friend Yvonne Smith told CBS2’s Jessica Layton.

Stunned co-workers of Wilson left flowers, candles and messages of peace after the 52-year-old was violently killed, stabbed to death on the third floor of the library where she was working as a security guard.

“Everybody was in chaos and panic,” one witness said.

Witnesses who did not want to be identified told CBS2’s Tony Aiello what happened after they saw the suspect charging toward the victim, then stabbing her.

READ MORE: CDC Issues New COVID-19 Guidance For Holiday Season

“We ran after him and by the staircase in the back, we held him down. He was screaming, ‘let me out, let me go.’ We just held him down until the cops arrived,” one witness said.

Co-workers were kneeling down around Wilson, yelling her name before a volunteer ambulance squad arrived.

“You’ll make it, they were assuring her that she’ll be making it,” one witness said. “When they took her, there was no pulse anymore.”

Friends say she lived on North Main Street in town with her children and just became a grandmother.

“She’s a wonderful lady. She’s very nice, she’s helpful. She’s generous,” one woman said. “I don’t know, but whoever did it, I hope they get punished real good.”

Without any idea who would want to hurt her, they now fear for their own lives in the community gathering space.

“I work here and I don’t feel safe. It can happen to anybody,” co-worker Roseline Willis said.

Police haven’t identified the suspect yet, but they say he is 25 years old. He was seen being escorted out of the library in handcuffs after he was caught.

MORE NEWS: New Video Shows Woman With Red Gas Can Inside Store Before Fire At Brooklyn Yeshiva

The library closed after the tragedy Tuesday and employees say it will be closed again Wednesday.