See a video of the "X-Wave" in motion here.
The three-piece apparatus is joined together by hinges and moves up and down, reported NewsOK.
Alyssa was sitting where the two pieces connect and when that section was in the air, she fell off the equipment. When she stood up to get back on the equipment, she was hit in the head as that section was coming down, knocking her to the ground.
When medical personnel arrived at the school, she was in cardiac arrest and CPR was being performed. She later died.
It alarms us to know that our school playgrounds could be unsafe -- or even deadly. Our heart goes out to Alyssa's family in this tragic time.