(WAVE) -- Cameras inside a school have allowed us to get an inside look at the power of an EF 4 tornado that destroyed towns from Pekin, Illinois to Henryville to Marysville, Indiana earlier this month.
Surveillance cameras inside Henryville Junior Senior High School were rolling as the storm destroyed their building.
Everything looked fine from outside Henryville Junior Senior High School just after school let out at 3 p.m. on Friday March 2, but as the buses pull back in and teachers come running out of the building to get the kids inside you start to understand that something dangerous is not far away.
In the background Henryville Auto Sales is still standing and that cafe where the bus ended up is still in one piece.
Just about four minutes after the last students got into the building the tornado hits and the cameras go black.
"The amount of energy and destruction that took place in such a short amount of time really boggles the mind," Assistant Superintendent Dr. John Reed said as he watched the video.
From the south end of the building near the playground the camera stays on as the tornado rips off the roof in the pieces.
It all happens in no more than 20 seconds.
About 80 staff and students were in the building at the time.
From the cameras in the library hallway you see a teacher walk past, then about 20 seconds later the feet run back the other way.
"It's amazing with the amount of destruction that occurred that there wasn't any injuries at all," said Dr. Reed.
Everyone inside was taking shelter in the offices.
From the camera in the hallway outside the elementary office as the wind comes in and the ceiling comes down, you get an idea of what the people still inside the Henryville school had to climb over to get out.
You never see the actually see the vortex of the tornado, just the suction and pressure and debris moving in different directions.
"It demonstrates the power of nature," said Reed.
The gym in the high school was definitely no match for that strength.
"The entire south end caves in with the force of the wind and then the vacuum of the tornado pulls all the debris back out of the gym," Reed explained.
When the dust settles, that gym is just a skeleton of what it once was, just like about 40 percent of the rest of the building.
Dr. Reed said they learned a big lesson from this not only how important drills for tornadoes and other national disasters are, but also about making them as serious as possible.
He says the district now plans to put obstacles in teachers way during the drills in the future so they are ready for anything.