INDIANAPOLIS — Cameras with a direct feed to the county sheriff office. Teachers who wear panic buttons. Smoke cannons in hallways.

These pieces of equipment are a big reason Southwestern High School in Shelbyville, Ind., has been referred to as "the safest school in America" since the airing of a segment on NBC's Today in 2015 (the network recently revisited the school). Shelbyville is about 27 miles southeast of Indianapolis.

The system was implemented in 2015 after the Indiana Sheriff's Association chose the school district for the first-of-its-kind security program. The school declined an interview about the program Wednesday, but an administrator previously discussed that school shootings can happen anywhere.

“I think that Newtown, Sandy Hook, really made people understand, made us all understand this could happen to us," Dr. Paula Maurer, superintendent of Southwestern Consolidated Schools, told WXIN-TV in Indianapolis when the program was revealed in 2014. “Now is the time to do something about it. We have some answers. We have the technology. We have ways to make our kids safer, and we have to do it.”

The school and law enforcement tout the real-time capabilities of the system to communicate with police and to track a suspect at the school. Here's how the safety program works:

• In the event of an active shooter, a teacher can press his or her emergency fob, which sets off a school-wide alarm and notifies local law enforcement. Students then barricade themselves in a corner out of view of a potential shooter looking through the window of a locked, bullet-proof door. Read more at USA Today