LA GRANGE, Texas - It's the last thing you expect to happen on your way home from school.

"We were going along fine, and then he started swerving all over the road and missing turns," said La Grange middle school student Karson Vega.

A La Grange bus driver suffered a health emergency while behind the wheel, which caused chaos on board.

"It was pretty scary. I thought we were going to wreck," Vega said. That's when the 13-year-old seventh grader stepped up.

He sat on the driver's lap, grabbed the wheel and drove the bus about two miles down Highway 71 while another student called police.

"I already accepted that if we were going to wreck, we were going to wreck," Vega said. "So I was just trying to do something so that we don't."

Karson managed to safely stop the bus.

The two middle schoolers are being credited for preventing what could've been a tragedy.

"I get teary-eyed and choked up thinking about…what he did makes me proud, but then what could have happened," said Karson's mom, Amber Vega. "So thankful that everyone is okay."

La Grange ISD said the boys acted heroically, and the district is now evaluating whether additional protocol is needed.

"I'll meet with our director of transportation, and we've discussed some ideas that we can maybe make sure that we share with our drivers in the future if they start to feel ill," said William D. Wagner, superintendent of La Grange ISD.

As for Karson, he's proud his actions saved lives.

"I think Karson was there for a reason because he normally doesn't ride the bus either," said his mom. "It just happened to be one of those days where I couldn't get him and he had to ride the bus."