Anxious parents and teachers arrived Tuesday morning for the first day of school in Uvalde, Texas — three months after the massacre at Robb Elementary School that left 19 children and two teachers dead.

No students or staff will return to the site of the deadliest school shooting in almost a decade, which has been shuttered permanently and will be razed to the ground, but tensions are still high in the community amid ongoing security concerns.

Towering new non-scalable fencing around the city’s public school campuses is still not finished and despite a heavy police presence for the first day back, families remain on edge.

Ashley Morales sent her son, Jeremiah, back to class — but only because she has no other choice as a working single mother.

She dropped him off outside Uvalde Elementary, where parents won’t be allowed inside.

“I’m just nervous, scared,” said Morales, whose son was a third-grader last year at Robb Elementary and lost three friends in the May 24 slaughter.

During a recent “Meet the Teacher” night, she felt a rush of anxiety walking down the school hall.

“Oh my gosh, it’s actually going to happen,” she said. “School is going to start.”

Although school already started weeks ago in many parts of Texas, officials pushed back the first day of class in Uvalde after a summer of unfathomable heartache, anger and revelations of widespread failures by law enforcement, who waited more than 70 minutes in the hallway while an 18-year-old gunman was executing children and teachers with an AR-15.

But despite pushing back the start of the year, Uvalde school officials said several enhanced security measures remain incomplete, including installing 500 additional cameras and new locks.

The Texas Department of Public Safety has committed to putting nearly three dozen state troopers on Uvalde campuses — but that is of no comfort to some families since there were more than 90 state troopers on scene during the attack.

More than 100 families in Uvalde signed up for virtual school, while others pulled their kids out of the district and placed them in private schools, including Sacred Heart Catholic School, where enrollment for the fall semester doubled compared to last year.

Adam Martinez told CNN he won’t be taking his son, third-grader Zayon Martinez, who survived the mass shooting in May, to class this week.

“I went and talked to my son and I told him, ‘They’re gonna have more cops. They’re gonna have higher fencing. And he wasn’t having it,” Martinez told the news outlet. “He said, ‘It doesn’t matter. They’re not gonna protect us.’”

Martinez said that both his son and daughter decided to study remotely last year because of fears for their own safety. 

Brett Cross, the uncle of 10-year-old Uziyah Garcia, who was shot dead inside his fourth- grade classroom, told CNN he has struggled with the idea of sending his own four children back to class this semester.

“You want your kids to be able to go and have that education and everything, but at the same time, you’re fearful that they’re not gonna make it out by the end of the day,” he said.

A damning report by a Texas House committee found that nearly 400 officers in total rushed to Robb Elementary after the shooting — but hesitated for more than an hour to confront the shooter.

Body camera and surveillance footage showed heavily armed officers, some holding bulletproof shields, loitering in the hallway but not advancing to the classroom.

Steve McCraw, head of the Texas Department of Public Safety, called the response “an abject failure.”

Last month, the Uvalde school board fired district police Chief Pete Arredondo, who McCraw and the House report accused of failing to take control of the scene and wasting time by looking for a key for a classroom door that was likely unlocked.

Still, the firing has not quieted demands for others to face punishment. One other officer — Uvalde Lt. Mariano Pargas, the acting police chief that day — has been placed on administrative leave.

With Post Wires