A senior on the pom squad at Tulsa's Edison High School is in an intensive care unit with a broken pelvis and two broken legs.
The young woman and another student were in a hammock and when the other student got up, the concrete pillar the hammock was tied to tipped over onto her, a spokesman with TPS said.
The path of Tuesday's nights tornado, that has a preliminary rating of EF-1 from the National Weather Service, went near the high school.
The spokesperson said if rain hadn’t softened the ground and taken some of the impact, he was afraid the accident could have been fatal.
We're told the girl sank about 6 inches into the ground when the pillar fell across her hips and rolled down her legs.
Hammocking has become a popular trend with campers and others.