A teacher lost her life when one 13-year-old student attacked and stabbed in total four teachers and two of his classmates in a public school in São Paulo, announced the Minister of Public Security Guierme Derite.

The teenager was taken to a police station where he will be interrogated, in the presence of his parents.

The other professors are not in danger while the students’ injuries are minor, said state education minister Renato Feder. A three-day mourning period was declared in honor of the professor.

Feder added that it was still too early to speculate on a motive for the attack, adding that the case was being investigated by police.

Under normal circumstances, military police would have taken the teacher to a hospital by helicopter, but because she had been hit, she was transported by car, resulting in her dying on the road, Derite told reporters outside the school in the west of Sao Paulo.

A physical education teacher restrained the student, preventing him from injuring others. “It was a heroic act. He immobilized him and made sure to take the knife from him. Without this heroic action, this tragedy would surely have been much greater.” added the minister.