MT. MORRIS, Mich. (WJRT) It's a small piece of metal that likely contributed to saving many people's lives at Oxford High School.

The Nightlock Lockdown is a door barricading device.

The devices, which are made and sold in Mt. Morris were attached to doors and floors inside Oxford High School.

Of course a lot of sadness, and heartbreak, and really feeling for the victims and their families.

"I've always been asked, if our locks have ever saved lives, and now they have. I've always said I hope they never have a chance to save a life but they have this time," said Nightlock Founder Jack Taylor.

Taylor said that more than 600 of his door barricading devices were used Tuesday afternoon when Oxford High School went into lockdown.

"We have two different styles of locks. One works with the floor plate and engages and slips in here and engages with the floor plate. This style works with a door frame. You just slip this in like that and it works with a hollow metal door frame," said Taylor. 

What this allows for is the door to remain closed even if a shooter were to shoot out the door's window and tried to open the door via the door knob.

Each door that has a device has its own wall mounted box with the devices inside, so once a school goes into lockdown, a teacher or student can easily run over and grab and insert the devices into the door and floor.

ABC12 News asked Taylor what went through his mind once he heard what happened Tuesday.

"We felt good. We knew that most of those kids were safe," he said. 

Those devices can withstand around 1,500 pounds of force.

Taylor told ABC12 News that Nightlock devices are in more than 300 school districts across the state, many of which are in mid-Michigan.

Demand for the devices by school districts really took off nine years ago, following the Sandy Hook school shooting in Connecticut.