A little more than a week earlier, Clarice Brazas gave a presentation on the recent mass shooting at a Buffalo grocery store to her ninth- and 10th-grade social studies students at the Academy at Palumbo in South Philadelphia.

But on Tuesday night, after 19 children and two adults were gunned down at an elementary school in Uvalde, Texas, Brazas couldn’t bring herself to prepare yet another explanation for the inexplicable.

As teachers across the region entered their classrooms Wednesday in the wake of the school shooting — the country’s second deadliest since the massacre at Sandy Hook Elementary 9½ years earlier — they confronted a wave of emotions: Fatigue at the weight of the latest tragedy on top of more than two years of pandemic-disrupted schooling. Frustration at the repetitive nature of the violence, and how vulnerable children were in the face of it. Anger at a society that had permitted such injustices to keep happening.

“We have seen the results of unfettered access to killing machines for years,” said Nicole Moore, principal of the Indian Mills School in Burlington County, who had readied her school with a counselor Wednesday and was prepared to field calls from anxious parents. “What will it ever take?”

Like many local educators and parents grappling Wednesday with the Texas tragedy, Moore voiced a worry that has become inescapable for many: Would her school be next?

“No one is immune to this violence,” she said. “It’s sickening.”

Others, like Brazas, felt a different kind of despair. “It’s just really overwhelming in a city where we have so many of our own kids killed by guns, or who have witnessed shootings,” she said.

Children in Philadelphia who have experienced gun violence “are expected to just show up to school every day and do what needs to be done,” Brazas said, starting to cry. While she feels the “terrible” pain of what children and families in Texas are experiencing, she said, “it’s terrible for our kids every single day that have to deal with the exact same things.”

» READ MORE: Too many lockdowns to count: Gun violence has touched everything at one Philly school

But the magnitude of the Texas shooting — and the tender age of the victims — was inescapable for teachers struggling with how to carry on with their jobs Wednesday.

Like other teachers, Lauren Costello said she often thinks about how she would protect her classroom if something were to happen — checking door locks and windows. Based on trainings she’s had in the West Chester Area School District that have told teachers to potentially be prepared to be locked down for hours, she now keeps food and hygiene products in her drawers.

She thought about the abruptness of Tuesday’s shooting. “As a teacher, not being able to say goodbye to your students is unfathomable,” said Costello, who teaches family and consumer science at Peirce Middle School. “I can’t imagine that being the end.”

And when one of her students told Costello on Wednesday that her mother seemed “really upset when she was at home,” she told the girl that the shooting was “absolutely tragic,” not knowing what more to say.

School officials tried to reassure families Wednesday — from providing resources about how to talk to children about violence, to promising stepped-up police presence. But some acknowledged the challenge in promising safety.

“Right here, right now, we’re safe here in Norristown,” Christopher Dormer, superintendent of the Norristown Area School District, said Wednesday. But he felt “a little bit of a powerlessness” as he considered the prospect of more gun violence at schools.

» READ MORE: How should schools respond to threats of violence? Experts give tips on quelling anxiety and assessing risk.

Noting a rise in behavioral issues and fighting that he attributed to children readjusting to in-person school after virtual learning, Dormer said schools need to do more to be safe places for all students, and to identify who might need greater supports.

Still, he said, he can’t control gun laws. He worries about the potential scope of damage of a tragedy closer to home: Robb Elementary and Sandy Hook Elementary, for instance, were both relatively small schools. Norristown High School has 2,500 students.

“The scale of it is just frightening,” Dormer said.

Some teachers expressed a resolve to carry on as normal. “I cannot let this fear corrupt my teaching,” said Lindenwold High School English teacher Larry Abrams, 54, of Cherry Hill.

A Navy veteran, Abrams said that he “never thought becoming a teacher could become potentially dangerous. But apparently it is.”

Parents like Heather McConnell, meanwhile, tried to instill a sense of security in their children Wednesday. But McConnell didn’t actually believe her own words.

“I’m tired of being afraid of sending my kids to school and trying to have a brave face and lying to them — saying they’re going to be safe in school. It’s bull—,” said McConnell, who has twin daughters in eighth grade in the Great Valley School District and a son in fifth grade at Delaware Valley Friends School. She cried at her kitchen table after dropping her son off Wednesday morning.

McConnell, who is furious about inaction on gun control, kept her children home from school when social media posts circulated last year warning of potential school shootings. “I knew people thought I was being irrational,” she said. “But I live in America, and it’s not irrational to be worried that you can’t go to a movie, or a grocery store, or school” without the risk of being shot.

She plans to send her daughters to a private, all-girls high school in part because she believes it will be a safer environment.

Amber Avellino, 37, of Mantua, said she fears for the safety of her children, ages 10 and 8, every day she drops them off at school.

“You don’t know if you’re going to pick them up. You don’t know what can happen,” she said Wednesday, choking back tears.

A stay-at-home mother, Avellino said she has considered possibly purchasing bulletproof shields to put in her children’s backpacks. She also wants her Gloucester County district to consider installing metal detectors.

» READ MORE: Philly will institute weapons scans of middle schoolers starting Monday. Critics say, ‘This is not OK’

”These are the things we have to think about as parents. How do I bulletproof my child today?” she said. “It shouldn’t be like that.”

John Bochanski has also struggled with the “dark thought” about danger his young children, who are 7, 5, and 3, might face in school. His oldest, a first grader in the Council Rock School District, has done drills in school to prepare for shootings, and “it breaks my heart that she’s going to grow up thinking that’s just what you do.”

He wasn’t particularly reassured by messages from schools on their efforts to prioritize safety.

The children in Texas likely did drills, too, he said. “At the end of the day, it’s not really going to amount to a whole lot.”

Brazas, the Philadelphia teacher, recalled how “unimaginable” the Sandy Hook massacre had felt nearly a decade ago. But in her gut, she said, she didn’t believe it would mark an end to school shootings.

“That’s what I was thinking when I got up this morning,” she said. “I would have to be in front of a bunch of kids on another day when there’s nothing good to say to them.”