A friendship between two straight-A teen girls unraveled over a mutual love interest and ended in a deadly confrontation inside a school classroom, according to reports.

Police said a 17-year-old girl allegedly took a steak knife and fatally stabbed her ex-friend Wednesday morning at Fitzgerald High School in Warren, Michigan, the Detroit Free Press reported.

The victim, 16, died two hours after she was impaled twice in the chest with the knife, according to officials.

More than 20 students and a teacher witnessed the teen love-triangle drama escalate around 8:30 a.m. when the suspect walked up to the victim.

“I froze. I didn’t know what to do. I just saw one of my friends just dying,” Victoria Oraczko, a 16-year-old student, told the Detroit Free Press.

Witnesses said the teacher tried to push the suspect away from the victim as one of the students called 911.

“There was blood everywhere she (the victim) ran,” junior Francesca Pascua told The Detroit News.

A resource officer attempted CPR on the wounded teen and she was rushed to St. John Macomb-Oakland Hospital, where she died during surgery, according to The Detroit News.

Authorities said the teen suspect was arrested without incident, but no charges have been filed against her yet.

“This is truly a tragedy on both sides,” Warren Police Commissioner Bill Dwyer told The Detroit News. “Our hearts and prayers go out to the families of the victim and the suspect.”

Police said recent text messages revealed both girls were romantically involved with the same student. The boy is reportedly cooperating with police.

“We don’t have all the facts yet, but we have enough information on what happened,” Dwyer said.