Lassalle

The student then stabbed Ms. Lassalle with one “violent” stroke, Mr. Bourrier said.

Students and teachers at schools across France stood for a moment of silence on Thursday in remembrance of Ms. Lassalle, who had taught at the school for decades and was described as caring, prepared and dedicated to her students.

The teacher, Agnès Lassalle, died on site, after colleagues and paramedics tried to stem the bleeding from a deep wound, which severed an aorta and punctured her right lung.

Mr. Bourrier said the student, whom he described as bright and hard-working, had been upset about a low grade in Spanish from Ms. Lassalle.

The deceased teacher, identified as Agnès Lassalle by local and national media and confirmed by a former colleague and student, had taught at the school for decades.