A teenager dressed in black barricaded himself in Robb Elementary School in the sleepy town of Uvalde, west of San Antonio, on Tuesday shortly after the mid-morning lesson break.
Opening fire with a handgun and reportedly an assault rifle, the killer, named as 18-year-old Salvador Ramos, shot dead 14 students and a teacher, in scenes reminiscent of the deadly 2012 Sandy Hook elementary school shooting.
The students, aged between seven and 10, were packed into ambulances, but were reported dead on arrival.
“He shot and killed horrifically, incomprehensibly, 14 students and killed a teacher,” Greg Abbott, Texas’ Governor, said.
It was not immediately clear how many people, in addition to the dead, were hurt but a local police officer said there were “several injuries”.
Earlier, Uvalde Memorial Hospital said 13 children were taken there. Another hospital reported a 66-year-old woman was in critical condition.
Shooter fired at police before running into school
The shooter engaged in a firefight with Texas border patrol officers before running into the school and barricading himself inside.
An unconfirmed video, shared online, appeared to show the moment he entered the building through a back entrance wearing all black and holding a gun.
Local residents reported hearing the sound of “firecrackers”.
The Uvalde Police Department said the suspect was killed by responding officers just after 1pm. He was named as Salvador Ramos, 18, a student who reportedly attended a nearby high school.
The Uvalde elementary school, which has 600 students enrolled, is located 60 miles east of the Mexican border. Uvalde itself is a town of some 16,000 mostly Hispanic and Mexican residents with a low crime rate.
Tony Gonzales, El Paso Congressman, said in a statement: “I am heartbroken for our South Texas community. It is devastating when our innocent children become the victims of senseless violence.”
The White House said President Joe Biden’s “prayers are with the families impacted by this awful event” and said he would address the incident later in the evening.
Mr Biden on Tuesday night ordered all flags at federal buildings to fly at half-mast.
The incident was the fifth deadliest school massacre in US history, and the second deadliest attack on a primary school since a former student of Sandy Hook in Connecticut murdered 28 students and teachers.
Gun deaths up since Biden took office
Mr Biden campaigned to put an end to America’s gun epidemic, but violence has only risen since he took office.
The US saw nearly 20,000 firearms homicides in 2020. That number increased by more than 50 per cent from 2020 to 2021, according to a recent FBI report.
The report said there were 61 “mass shooting incidents” in the US in 2021, representing a nearly 100 per cent rise in such attacks from 2017, which saw 31.
The most recent was only 10 days ago in Buffalo, New York, where a white gunman opened fire on black supermarket shoppers in a racially motivated attack.
Days before the Buffalo shooting, a gunman walked into a hair salon in Dallas, Texas, and shot and wounded three people.
Despite recurring mass-casualty shootings, multiple initiatives to reform gun regulations have failed in the US Congress, leaving states and local councils to enact their own restrictions.
Texans allowed to carry guns without licence or training
Texas has one of the US’s most liberal gun laws in the country and has suffered some of the deadliest attacks.
Mr Abbott last year signed a law that allowed Texans to carry handguns without a licence or training.
The National Rifle Association’s annual meeting is set to be held in Houston starting on Friday. Former President Donald Trump, Mr Abbott and Texas Senator Ted Cruz are among those scheduled to address the gathering.
Democratic Senator Chris Murphy, who represents the town devastated by the Sandy Hook shooting, said he was working to directly offer his condolences to the Texas senators.
“People in Texas have been through way too many of these, from El Paso to Sutherland springs,” he said. “this is just a trail of horror that no state should ever have to go through.”