A gunman killed 15 people – 14 of them children – at a small Texas elementary school Monday afternoon, authorities said.

Texas Gov. Greg Abbott said the shooter walked into Robb Elementary School in Uvalde around noon Central time and opened fire with a handgun. The shooter was killed by responding police, Abbott said.

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

Uvalde is a city of about 16,000 people about 80 miles west of San Antonio, and local authorities were planning a press conference Monday afternoon.

Anxious parents were reuniting with surviving children all afternoon.

Two patients were dead when they arrived at Uvalde Memorial Hospital, spokesperson Tom Nordwick told USA TODAY. Thirteen children are being treated in the emergency room of Uvalde Memorial Hospital and 45-year-old man was brought in after suffering “a graze,” Nordwick said.

A 66-year-old woman is in critical condition and one child is being treated at University Health, the San Antonio hospital said in a statement released on social media. 

Multiple law enforcement agencies including the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Federal Bureau of Investigation were on scene Tuesday afternoon. The school district said students have been transported to the city’s civic center and encouraged parents are encouraged to pick up their children.

“We are aware of this tragic incident,” FBI Special Agent Carmen Portillo said in a statement. “At this time, it’s too soon to determine the extent of our involvement.”

Earlier, the district said that all schools in the district were locked down because of gunshots in the area. Uvalde is about 85 miles west of San Antonio.

Robb Elementary School has an enrollment of just under 600 students.