A gunman killed 15 people – 14 of them children – at a Texas elementary school, Gov. Greg Abbott said Tuesday. It marks the deadliest school shooting in the state’s history. 

Abbott said the 18-year-old shooter walked into Robb Elementary School in Uvalde around noon Central time and opened fire. The shooter was likely killed by responding police and had a handgun and possibly a rifle, Abbott said. 

“He shot and killed, horrifically, incomprehensibly, 14 students, and killed a teacher,” Abbott said Tuesday afternoon. “He himself is deceased. It is believed that responding officers killed him.”

He said two responding officers were struck by gunfire but weren’t seriously injured.

Officials have not revealed a motive for the shooting, but have said the shooter was a resident of the community. Abbott identified the gunman as Salvador Ramos.

Uvalde is a city of about 16,000 people about 85 miles west of San Antonio. The shooting came four years after a gunman fatally shot 10 people at Santa Fe High School in the Houston area.

It is the deadliest shooting at a U.S. grade school since the shocking attack in Sandy Hook, Connecticut, almost a decade ago, fueling a fresh round of grief and despair.