5 dead, 20 injured at Thailand's prestigious Debsirin Nonthaburi School

A 14-year-old student killed his grandparents before opening fire at the prestigious Debsirin Nonthaburi School just north of Bangkok. He killed 5 teachers and wounded ~20 others (mostly students between age 12-14) before ending his own life inside the building.

The shooting started around 10:00 AM local time. He fired at least 26 bullets using a 9mm handgun belonging to his grandfather. Like most school shooters in the United States, he was found with 34 additional rounds of unused ammo and a functional firearm when he ended the attack on his own terms rather than searching for more victims. Police had not located the shooter when he turned the gun on himself.

Unlike school shootings in the United States, unarmed EMS workers entered the school before police “cleared the scene” and transported victims including the gunman. After sustaining a self-inflicted headwound, the 14-year-old still had a pulse when EMS workers transported him to the hospital where he later died.

A classmate told local news the 14-year-old assailant “suffered stress from studying”. Like shootings in the US, warning signs were missed as the teen posted photos on Instagram in April with the firearm he used. He also searched online for content and websites related to mass shootings (side note: I’ll bet he was engaging with TCC content).

A teacher speaking anonymously said he was a “good kid with good study records” and he had never been aggressive at school.

Police believe the attack was planned in advance with “clear steps and clear goals”. Authorities also believe he was deliberately targeting teachers during the attack that continued for about one hour from the first to final shot.

The shooting took place at a huge grade 6-12 school with about 3,100 students and 150 teachers.

The school was founded by King Chulalongkorn (Rama V) in 1885, the original historical campus is located in the Pom Prap Sattru Phai district of central Bangkok. It’s one of Thailand’s most prestigious and historic secondary schools with alumni including prime ministers, scholars, and writers.

Last month, two 9th grade students opened fire inside San Jose National High School in Tacloban City. Local officials cite “systemic failures” in missing the clear warning signs of mass violence.

In May, a 13-year-old student opened fire near the principal’s office of Instituto São José in Brazil on Tuesday. Two were killed and two were wounded before the student surrendered.

In April, at least eight students and one teacher have been killed, and 13 others injured (6 critical), following a shooting at Ayser Calik Secondary School in Kahramanmaras, Turkey and at least 16 people were injured after a teenage former student opened fire at Ahmet Koyuncu Vocational and Technical Anatolian High School in Siverek, Turkey.

In March, a 15-year-old student entered the private Anton Makarenko High School, in the Mexican coastal municipality of Lázaro Cárdenas, Michoacán, and killed two of his female teachers.

In November 2025, 97 students were injured by a TCC-inspired student who committed a shooting/bombing at his school. The 17-year-old student had 2 replica AR-15 airsoft rifles (real guns are very hard to get in Indonesia) when he detonated seven IEDs inside National High School 72 during afternoon prayers.

David Riedman, PhD is the creator of the K-12 School Shooting Database and a tenure-track professor. Listen to my podcast—Riedman Report: Risk, AI, Education & Security—or my interviews on Freakonomics Radio and the New England Journal of Medicine.