The United States is the only developed country where school shootings are relentlessly repeated, like the one that mourned an elementary school in Texas on Tuesday, leaving 18 children dead.

These are the deadliest shooting massacres in America’s classrooms in the last two decades.

An 18-year-old teenager killed 19 students and two adults at Robb Elementary School in the town of Uvalde, Texas, located between the city of San Antonio and the border with Mexico. The suspect also died.

A 15-year-old teenager has killed four students in cold blood and wounded six others, as well as a teacher, on high school grounds in Oxford, Michigan, a small town north of Detroit. The shooter was charged with “terrorist act” and “murder” and, unusually, his parents were also prosecuted.

A 16-year-old teenager marked his birthday by shooting students at his high school in Santa Clarita, California, killing two classmates and wounding three others before attempting suicide. The victims were between 14 and 15 years old.

A 17-year-old teenager gunned down 20 people at his high school in Santa Fe, Texas: two adults and eight youths die. The attacker has been jailed ever since.

On Valentine’s Day, a 19-year-old Nikolas Cruz unloaded his semi-automatic rifle at Marjory Stoneman Douglas High School in Parkland, Florida, from which he had been expelled for disciplinary reasons. He left 17 dead, most of them teenagers. The shooter was arrested.

A 15-year-old teenager shot and killed two other students of the same age at Benton Kentucky High School. Another 18 people were injured by bullets or in the chaos created by the shooting.

A 26-year-old student shot and killed nine people at Umpqua University. Wounded, he shot himself in the head.

A man killed seven people at the small Oikos University in Oakland, California. The shooter, a former student of Korean origin, was arrested and died seven years later in prison.

After shooting his mother, 20-year-old Adam Lanza killed 26 people, including twenty 6- and 7-year-olds, at Sandy Hook Elementary School. He later committed suicide. America is still haunted by this massacre because of the many children killed.

A South Korean student has killed 32 people with his two semi-automatic pistols, before committing suicide at that famous institution of higher education.

Two heavily armed Columbine High School students, aged 17 and 18, killed twelve classmates and a teacher before committing suicide in the library. The death toll would have been even worse if the attackers had managed to detonate their homemade bombs.

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