All 19 of the children killed in a shooting at a Texas elementary school on Tuesday were in the same fourth grade classroom, according to a state public safety official.

The 18-year-old gunman killed at least 21 people in the school, including 19 children and two teachers. The shooter was also killed on the scene by law enforcement officials.

SUSPECTED UVALDE GUNMAN DISPLAYED VIOLENT TENDENCIES BEFORE SCHOOL MASSACRE: REPORTS

It’s not clear whether the teachers were in the same classroom, but two of the adults identified among the deceased victims were co-teachers in a fourth-grade classroom, according to reports. Those teachers were identified as Eva Mireles and Irma Garcia.

An anonymous law enforcement official told the Associated Press that a Border Patrol agent shot and killed the gunman after rushing into Robb Elementary School without waiting for backup. The shooter was hiding behind a barricade and engaging in gunfire with other officials, this source said.

Salvador Ramos, an 18-year-old who attended a nearby high school, has been identified as the suspected gunman. He also reportedly shot his grandmother before the school attack, and officials said she was still in critical condition as of Tuesday night.

CLICK HERE TO READ MORE FROM THE WASHINGTON EXAMINER

The gunman was wearing body armor and a backpack when he entered the school, and he made it into several classrooms before being killed, Sgt. Erick Estrada of the Texas Department of Public Safety told CNN's Anderson Cooper. The shooter was armed with at least one of the two military-style rifles that he had purchased for his 18th birthday, according to state Sen. Roland Gutierrez, who said he was briefed by state police.

Uvalde is a town of roughly 16,000 people, situated between San Antonio and Del Rio. The town is dozens of miles away from the southern border and has a Border Patrol station.

This story is developing and will be updated.