HARROWING ACCOUNTS EMERGED today of the ordeal faced by survivors of the school shooting in Uvalde, Texas, fanning public fury over the massacre even as the deeply traumatized town prepared for a visit Sunday by US President Joe Biden.

The haunting stories told by young students who were forced to play dead as a heavily armed gunman continued a methodical spree — killing 19 students and two teachers — have been underscored by accounts of the slow reaction by police during the drama.

Ten-year-old Samuel Salinas was sitting in his fourth-grade classroom when the shooter, later identified as Salvador Ramos, 18, barged in with a chilling announcement: “You’re all going to die.”

Then “he just started shooting,” Salinas told ABC News.

Texas authorities belatedly admitted Friday that as many as 19 police officers were in the school hallway for more than an hour without acting, thinking the shooter had ended his killing.

“From the benefit of hindsight… it was the wrong decision, period,” said Texas Department of Public Safety director Steven McCraw.

Ramos, who carried two assault-style rifles, was finally killed by police.

Uvalde survivors have described making desperate, whispered pleas for help in 911 phone calls during his assault. Many played dead to avoid drawing the shooter’s attention.

Eleven-year-old Miah Cerrillo even smeared the blood of a dead friend on herself as she feigned death.

Samuel Salinas said he thinks Ramos fired at him, but the bullet struck a chair, sending shrapnel into the boy’s leg. “I played dead so he wouldn’t shoot me,” he said.

Another student, Daniel, whose mother would not provide his last name, said he saw Ramos fire through the glass in the classroom door, striking his teacher.

The bullets were “hot,” he told the Washington Post, and when another bullet ricocheted and struck a fellow student in the nose, he said he could hear the sickening sound it made.

Though his teacher lay on the floor bleeding, she repeatedly told the students, “‘Stay calm. Stay where you are. Don’t move,’” Daniel recalled.

He was finally rescued by police who broke the windows of his classroom. Since then, he has had recurrent nightmares.

A troubling timeline 

President Joe Biden will visit Uvalde on Sunday to again make the case for gun control, as activists set about galvanizing voters on the issue in the run-up to November’s midterm election.

Despite the scourge of mass shootings, efforts at nationwide gun control have repeatedly failed, though polls show broad support from Americans.

Speaking at a University of Delaware commencement on Saturday, Biden — himself a grieving father twice over — evoked the image of parents preparing to bury their children in Texas, and lamented “too much violence. Too much fear. Too much grief.”

“We have to stand stronger,” he told the graduates at his alma mater.

The Uvalde shooting was the deadliest since 20 children and six staff were killed at the Sandy Hook school in Newtown, Connecticut in 2012.

McCraw revealed a series of emergency calls — including by a child begging for police help — that were made from two adjoining classrooms where the gunman was barricaded.

But he said the on-scene commander believed at the time that Ramos was in there alone, with no survivors, after his initial assault.

“I’m not defending anything, but you go back in the timeline, there was a barrage, hundreds of rounds were pumped in in four minutes, okay, into those two classrooms,” McCraw said.

“Any firing afterwards was sporadic and it was at the door. So the belief is that there may not be anybody living anymore.”

McCraw separately told reporters, however, that a 911 call received at 12:16 pm reported eight or nine children still alive.

As many as 19 officers were outside the classroom door at that time, according to McCraw’s timeline.

McCraw said one caller — a child who dialed 911 multiple times — begged for police to come. Her final call was cut off as she made it outside.

Texas Governor Gregg Abbott told journalists who grilled him during a testy news conference Friday that he was given inaccurate information in the wake of the massacre.

“I was misled,” Abbott said. “The information that I was given turned out in part to be inaccurate, and I’m absolutely livid about that.”