What started as a preschool celebration in Huntington Beach on Tuesday ended with a school lockdown after a teacher was shot in the leg with a BB gun.

Teachers and staff were waving goodbye to their 4-year-old students at Oak View School around 11:35 a.m. on Tuesday as parents paraded by in cars for the end of the year celebrations when they came under fire.

MORE NEWS: Buttigieg to lecture Notre Dame students about ‘The Nature of Trust’

Staff, some dressed as superheroes, reportedly heard the metal ping of pellets hitting a metal hand rail over the Disney music blaring in the background, Oak View School District board president Gina Clayton-Tarvin told The Orange County Register.

“They also heard from the community somebody scream out of the windows: ‘Shut up!’ because apparently the parents and the kids were driving through in their vehicles and they were honking their horns in celebration,” Clayton-Tarvin said.

That’s when teacher Kathy Blythe told NBC4 her colleague was struck.

“She came over to me and she said, ‘I think I’ve been shot,’ and I said, ‘What?!’ She said, ‘I think I’ve been shot,’” Blythe said.

“She had blood all around here,” Blythe said, pointing just above her knee, “and a little hole.”

School officials immediately put the campus on lockdown, teachers ran inside and took cover, while parents and their kids were sent home.

MORE NEWS: Students, staff demand university fire security administrator over military leadership at Guantanamo Bay

“It was a really really great event” until things turned tragic, Clayton-Tarvin told the Register.

“You know it was a really nice event and unfortunately it turned really dark,” she said. “It’s really sad for us.”

Huntington Beach police responded to the scene and are now requesting cell phone videos from the public as they investigate.

Blythe told NBC4 the teacher who was hit seemed more concerned about her students than the injury.

“The whole time she’s in there, she’s like, ‘Are the kids ok? Are the kids ok? I’m so sorry this happened,’” she said.

Teachers at the school said the ordeal was “heartbreaking.”

“We have so many activities in the community and the community I feel like they protect our school,” teacher Norma Vasquez said. “So for this to happen, it was just a broken heart.”

“I’m heartbroken,” Blythe said. “I’ve been here 18 years and unfortunately our world is not a happy place right now.”

The injured teacher, who was not identified, was taken by paramedics to a hospital and treated for the minor injury, The OCR reports.