A 16-year-old girl’s quick thinking and her level head under pressure helped her save her brother’s life along a Denton, Texas highway.

Cayaana Kniper, a Krum High School student, used the Heimlich maneuver to stop her brother from choking. She learned it in school two years ago.

“It (was) just one of those things where you act,” she said.

She said she noticed something was wrong with her 7-year-old brother, Avery, while she was driving her younger siblings to church April 22 on U.S. 380.

WATCH VIDEO OF A 16-YEAR-OLD WHO SAVED HER BROTHER

“He was choking,” she said. “But I thought, ‘Oh no, he’s joking. It’s fine,’ and then a couple seconds later, he kept doing it, and I asked if he was OK, and his face was red.”

Her brother was choking on a piece of bread he brought with him from home.

“The bread was too big,” he said. “Even though I chewed it, it got stuck in the middle of my throat.”

His older sister jumped into action. She pulled the car to the side of the road, took her brother out of the car and performed the Heimlich maneuver.

“I knew I had to act quickly,” she said. “I didn’t know how fast someone could die of suffocation, so if anything was going to be done, it would have to be done now.”

She said she was glad she learned the maneuver in school.

“If I hadn’t done that, then I wouldn’t have known at all what to do, and today could have been a very different day,” she said.

Her brother said he is grateful to his big sister.

“I was glad she was there that day, because if she wasn’t there, I would be dead already,” he said.

Cayaana Kniper said the experience gives her confidence in the career she’s decided to pursue — nursing.