Authorities tell Action News the three fourth graders saw the jogger wearing a dark hooded sweatshirt and thought he had a mask and gun.
Souderton Area Schools Superintendent Fred Johnson commended the students for "doing the right thing" by reporting their suspicions to school officials.
Parents were allowed to pick up their children Thursday afternoon after West Broad Elementary School in Souderton was locked down following a report of a person with a 'possible gun' outside the school.
Police were on hand to help with the dismissal.
But before the lockdown was lifted there were some very tense moments in Franconia Township.
The report came at 1:40 p.m. of a masked gunman on the playground of the West Broad Elementary School in Souderton. The school went into lockdown.
All 530 children, grades K-5, were kept safe inside while police and tactical units responded and started a search.
Roads were shut down. Residents were even kept from returning to their houses. School Superintendent Fred Johnson told Action News briefed reporters on what was happening.
"What we know at this time," he said as the incident unfolded, "is that a student, we don't know if it was male or female, said that he or she saw someone on the playground, looked like he had a ski mask on and had a gun. The student immediately alerted the teacher, principal and the school went into lockdown."
The principal sent out an email to parents immediately, and some rushed to the scene. They looked on as police looked for a gunman and found nothing.
Dismissal happened a little bit later than usual, but as normal. Still, it was a very anxious time for parents as they waited for the all-clear.
"I just wanted to get down here," said parent Tracy Seiving, "and get to them as soon as we can. They're protected. As long as they're in the building and safe and nobody's in there with them we're okay."
Again, nothing was found. School officials and police said they have to take all these reports seriously, and they will be reviewing Thursday's response.