The Jewish day school on the Main Line evacuated students for an early dismissal after the discovery of an unclaimed bag of ammunition.
Jack M. Barrack Hebrew Academy sent students home early Wednesday after a bag containing ammunition was found on campus.
A security officer discovered the bag around 10 a.m., and administrators immediately contacted the Radnor Police Department, according to a letter sent to parents by Sharon Levin, head of school.
Students and staff stayed in the gymnasium of the Jewish day school in Bryn Mawr as police searched the building and inspected the bag, according to Amy Malissa Hersz, manager of marketing and communications.
Once police had declared the building safe, parents were called at 12:30 p.m. and told "everything's fine; come get your kids," said Hersz.
"We were told that there was no imminent danger; everything we did was a precautionary measure," she said. "We did it by-the-book in terms of our emergency plans."
Students remained calm throughout the process, Hersz said.
"They were incredible. They knew it was time to listen and sit and pay attention, and time to be serious, but they weren't panicky," Hersz said. "As a mom, I can tell you they were super impressive."
The school is expected to reopen Thursday and will have additional police presence on campus as they investigate.
The incident came just a week after police arrested a 17-year-old student at nearby Radnor High School after she wrote about wanting to commit mass murder at her school.