PERRY, Iowa — A teen armed with a shotgun and a handgun unleashed terror at an Iowa high school on the first day of classes in the new year, authorities said, killing a sixth grader and wounding five others as people hunkered down in classrooms, barricaded offices and fled the barrage of bullets.

The suspect, a 17-year-old student at the school in Perry, died of what investigators believe was a self-inflicted gunshot wound, an Iowa Division of Criminal Investigation official said. An administrator, later identified by his alma mater as Perry High School Principal Dan Marburger, was among those wounded Thursday as students returned from winter break.

Authorities identified the shooter as Dylan Butler but provided no information about a possible motive. Two friends and their mother who spoke with The Associated Press said Butler was a quiet person who had been bullied for years.

Authorities said Butler had a pump-action shotgun and a small-caliber handgun. Mitch Mortvedt, the state investigation division’s assistant director, said during a news conference that authorities also found a “pretty rudimentary” improvised explosive device and rendered it safe.

A law enforcement official briefed on the investigation said federal and state investigators were interviewing Butler’s friends and analyzing Butler’s social media profiles, including posts on TikTok and Reddit.

Shortly before Thursday’s shooting, Butler posted a photo on TikTok inside the bathroom of Perry High School, the official said. The photo was captioned “now we wait” and the song “Stray Bullet” by the German band KMFDM accompanied it. Investigators have also found other photos Butler posted posing with firearms, according to the official, who was not authorized to publicly discuss details of the investigation and spoke to AP on condition of anonymity.

Sisters Yesenia Roeder and Khamya Hall, both 17, said alongside their mother, Alita, that Butler was bullied relentlessly since elementary school, but it escalated recently when his younger sister started getting picked on, too.

“He was hurting. He got tired. He got tired of the bullying. He got tired of the harassment,” Yesenia Roeder Hall said. “Was it a smart idea to shoot up the school? No. God, no.”

Calls to Perry Community Schools’ Superintendent Clark Wicks, as well as school board members, were unanswered Thursday, and an emailed request for comment was not immediately returned.

Police arrived within minutes after an active shooter was reported at 7:37 a.m. Thursday, authorities said.

Perry High School senior Ava Augustus was awaiting a counselor in a school office when she heard three shots. Unable to flee through a small window, she and others barricaded the door and were ready to throw things if necessary.

“And then we hear ‘He’s down. You can go out,’” Augustus said through tears. ”And I run and you can just see glass everywhere, blood on the floor. I get to my car and they’re taking a girl out of the auditorium who had been shot in her leg.”

Three gunshot victims were treated at Iowa Methodist Medical Center in Des Moines, a spokesperson said. Others were taken to a second hospital, a spokesperson for MercyOne Des Moines Medical Center confirmed.

Mortvedt said one person was in critical condition but the injuries didn’t appear to be life-threatening, and the others were stable.

In a Facebook post, Marburger’s daughter said he was in “surgery all day, and is currently stable.”

Claire Marburger called her father a “gentle giant” who would want more attention on the other victims and their families, and less on himself.

On Thursday night, hundreds of people gathered for a candlelight prayer vigil at a park where hours earlier, students had been brought to reunite with their families after the shooting. Bundled up against freezing temperatures, they listened to clergy from many faiths and heard a message of hope in both English and Spanish.

A post on the high school’s Facebook page said it would be closed Friday and counseling services would be available for students, faculty and others in the community.

“This senseless tragedy has shaken our entire state to its core,” Gov. Kim Reynolds said.

In Washington, President Joe Biden and U.S. Attorney General Merrick Garland were briefed on the shooting.

Mass shootings across the U.S. have long brought calls for stricter gun laws from gun safety advocates, and Thursday’s did within hours. But the idea has been a non-starter for many Republicans, particularly in rural, GOP-leaning states like Iowa, which will hold its first-in-the-nation presidential caucuses Jan. 15.

As of July 2021, Iowa does not require a permit to purchase a handgun or carry a firearm in public, but it does mandate a background check for anyone buying a handgun without a permit.

Perry has about 8,000 residents and is about 40 miles (65 kilometers) northwest of Des Moines, on the edge of the state capital’s metropolitan area. It is home to a large pork-processing plant and low-slung, single-story homes spread among trees now shorn of their leaves by winter. The high school and middle school are connected, sitting on the east edge of town.

The high school is part of the 1,785-student Perry Community School District. Perry is more diverse than Iowa as a whole. Census figures show 31% of its residents are Hispanic, compared with less than 7% statewide. Those figures also show nearly 19% of the town’s residents were born outside the U.S.

Zander Shelley, 15, was in a hallway when he heard shots and dashed into a classroom, according to his father, Kevin Shelley. Zander was grazed twice and hid in the classroom before texting his father.

Kevin Shelley, who drives a garbage truck, told his boss he had to run. “It was the most scared I’ve been in my entire life,” he said.

He later posted a photo on Facebook of his son being treated at the Methodist Medical Center and said the boy was feeling fine.

“I am still shaking,” he added, “and tho I dont show it I’m not OK.”