An elementary school teacher was stabbed Friday as she was watching her students play in a Long Beach park.

53-year-old Kellye Taylor was at a playground near the Huntington Academy, watching students play as they spent a day outside on the school’s “Fun Friday”, reports the San Francisco Chronicle. A man suddenly approached Taylor from behind and stabbed her in the neck.

When they saw that their teacher had been stabbed, some of the children reportedly ran across the street to the school for help.

Officers soon arrested 50-year-old Steven Brown, the father of Taylor’s grandchildren, on suspicion of murder and found the “sharp instrument” that they believe he used to stab her. He is currently being held on $1 million bail.

Pamela Huffman, who is another teacher at the school and Taylor’s younger sister, told authorities that two other teachers were at the park when Taylor was stabbed, reports the Long Beach Press-Telegram.

“How could they do something like this in front of these babies,” Huffman told the Press-Telegram in an interview. “All I could do was run to her. I saw her slip away. I knew she wasn’t going to make it.”

According to Huffman, Taylor had custody of her grandchildren and had been caring for them, which was the cause of her strained relationship with Brown. Police say they have not yet determined a motive for the stabbing.

When school resumes on Monday, counselors will be at the school to help both students and staff.