UVALDE, Texas (KXAN) — At least 18 children and one teacher were killed in a mass shooting at Robb Elementary School in Uvalde Tuesday, in what Gov. Greg Abbott later called a “horrific tragedy.”

“What happened in Uvalde is a horrific tragedy that cannot be tolerated in the state of Texas,” Abbott said.

In a follow-up statement just before 6 p.m. Tuesday, Abbott directed all Texas flags be lowered to half-staff across the state Tuesday until sunset May 28.

Uvalde reported an active shooter situation at the elementary school shortly before noon Tuesday. During a press conference later that afternoon, Abbott identified the shooter as 18-year-old Salvador Ramos, who is believed to have been killed by responding officers.

During an Election Day speech Tuesday evening, incumbent Texas Attorney General Ken Paxton called for prayers for the victims and their families.

“Whether these people are Republican or Democrat, they’re fellow Texans and fellow Americans,” he said. “We love them and we’re going to — we’re going to pray for them, we’re going to try to help them.”

Dade Phelan, speaker of the Texas House, called Tuesday’s mass shooting “a horrific & heartbreaking situation” in a tweet Tuesday.

U.S. Sen. Ted Cruz, R-Texas, called the mass casualty event a “horrific shooting” and commended efforts from law enforcement personnel who responded to the scene.

“Heidi & I are fervently lifting up in prayer the children and families in the horrific shooting in Uvalde,” Cruz said in a tweet. “We are in close contact with local officials, but the precise details are still unfolding. Thank you to heroic law enforcement & first responders for acting so swiftly.”

Democratic gubernatorial candidate Beto O’Rourke, said “our broken hearts are with Uvalde” in a tweet Tuesday afternoon. He later added: “The moment to stop Uvalde was right after Sandy Hook. After Santa Fe High. After El Paso. Instead, Abbott made it easier to carry guns in public. The moment to stop the next slaughter is right now.”

U.S. Sen. John Cornyn, R-Texas, referred to the shooting as “every parent and teacher’s worst nightmare” in an official statement Tuesday evening.

“This is an excruciatingly difficult time for the tight-knit Uvalde community and for all Texans as we mourn this terrible tragedy,” the statement read in part. “My heart goes out to those in the hospital receiving care and to the loved ones of those who lost their lives. As a parent, the pain they must be feeling is unimaginable.”

Rep. Tony Gonzales (R-23), who represents Uvalde, said in a tweet: “My heart breaks for the city of Uvalde. Pray for our families.”

Texas State Rep. Erin Zwiener (D-45) said her thoughts are with the South Texas community following Tuesday’s mass shooting.

“My heart breaks for the parents, grandparents, sisters and brothers of those little children, and for the families of the adults who were killed or injured today in Uvalde, Texas,” she said in a tweet.

Texas State Rep. James Talarico, tweeted: “Nothing will change until we love our children more than our guns.”

Travis County Judge Andy Brown said “Texas deserves action” in a tweet following the shooting.

“Too many children and educators have lost their lives to gun violence. No parent should have to go through this,” Brown tweeted in part.

Harris County Judge Lina Hidalgo said today’s deaths are the result of “another senseless act of gun violence in Texas.”

“How much longer will we be willing to put the interests of the gun lobby over the lives of innocent people?” she tweeted.

U.S. Rep. Joaquin Castro, D-San Antonio, called Tuesday’s mass shooting “a parent’s worst nightmare.”

“Uvalde is a wonderful, tight-knit community west of my hometown of San Antonio. My heart goes out to the community and the families in Uvalde devastated by gun violence today,” he tweeted. “This is a parent’s worst nightmare. We need gun reform now.”

Julian Castro, the former mayor of San Antonio and United States Secretary of Housing and Urban Development, said “this is not normal or inevitable.”

“My heart goes out to the Uvalde community. This is not normal or inevitable,” his tweet read in part. “Children and parents should NEVER be accustomed to this violence.”

Greg Casar, the former Austin City Council member and District 35 United States House of Representatives candidate, said Tuesday no community should have to endure what unfolded in Uvalde.

“Every single lawmaker at every level of government should support gun reform to make our communities safer & prevent tragic, destructive shootings like this,” Casar tweeted.

Austin Mayor Steve Adler said he’s joining the rest of Texas to pray for those killed and injured in Tuesday’s mass shooting.

“Today’s school shooting in Uvalde was heartbreaking and horrific,” he tweeted, adding: “When will we act in meaningful ways to stop this?”

Nationally, United States Press Secretary Karine Jean-Pierre confirmed President Joe Biden has been briefed on the “horrific news” of the shooting and will continue to receive updates as they are made available.

Biden will deliver an address on the shooting at 7:15 p.m. CST from the White House’s Roosevelt Room.