SOUTH BEND — Greene Intermediate School administrators put the school on lock down after students told staff members they first saw a gun while riding on the bus.

Police questioned four students but they ended up detaining and questioning five students.

They say all of them handled the gun at some point on the bus. Their ages range from 11 to 14 years old.

Police say one student was responsible for bringing the gun on the bus.

While police are trying to figure out how that student got a hold of the gun, parents are upset the school didn't contact them sooner.

Kim Keen came to South Bend 14 years ago because she wanted peace and quiet. She never expected this to happen.

"One of the reasons why we moved out to the country is we wanted to be in the country. You know I didn't want the inner city problems,” said Keen.

Unfortunately she's learning those problems can happen no matter where you live.

“The gun was on the school bus and was passed around among several students,” said Sgt. William Redman.

The loaded 9mm handgun was put inside in a backpack and then taken inside the school.

"Anytime you have a weapon of any kind in or around a school that puts everybody in danger,” said Sgt. Redman.

School administrators locked down the school and found the gun inside a locker.

Hours later, parents still fear for their children's safety.

"That's scary, really scary,” said Keen. "Actually I think I'm going to go down and pick up my daughter from school right now after you leave.”

Other parents are scared as well.

"You send them to school and you think they're going to be safe,” said Sara Zolman.

Safety isn't their only concern. Many parents say the school should have notified them immediately.

"In this particular case we felt that once we had the individuals in custody, the weapon in custody the danger was removed and there was no need to notify parents and so forth to come pick up children,” said Dr. Zimmerman.

The school did send a letter home with students notifying parents of what happened. When the gun was found it was jammed, preventing if from firing.

The superintendent says it's likely all five students will be expelled.