NBC NEWS -- Police continue their search for evidence and answers in Oregon, after a school shooting Tuesday left a student and the gunman dead and a teacher wounded.
On that note, a group of educators in Iowa have created a device they say can help save lives during an active shooter situation at a school.
It's a simple metal piece that is slipped on a door closer and can resist up to 550 pounds of force.
Daniel Nietzel, is a teacher in Muscatine, Iowa, says the slam of a locker makes him worry it could be a shooter.
"It's a fact that we live in a society now where there is potential for you to be in the middle of a lesson and someone coming into your school with a gun to kill innocent children," he said.
He wanted to take it into his own hands and came up with the invention "The Sleeve".
"Being a school counselor, it really hits me. You never want to deal with that and you cannot say that it will never happen here, the reality of the situation is that it can," said Edwin Colon, VP of production for Fighting Chance Solutions.
Right now, most classroom doors only lock from the outside, and during the Sandy Hook shooting, a teacher was shot when she stepped into the hallway to lock the door.
"She wasn't even involved in the main incident in the kindergarten classroom. She was out of that but she was still shot," said Nietzel.
This new invention works to prevent that. It quickly slips on to keep the shooter out, and comes off in one second for evacuation.
"The science is there. Our engineers did all the testing," said Colon.
To top it all -- they've made it affordable for teachers -- to put in their own classrooms even if school districts won't fund it.
"We have the potential to save lives and to me there is nothing more noble and save lives in the profession that we all chose to go into, something very near and dear to our hearts," said Nietzel.