GRAND RAPIDS, Mich. (WOOD) — As police search for two people who threw concrete at cars on US-131, one man is warning them about the consequences, especially if someone gets hurt.

Jeff Kooiman knows about the consequences firsthand. He and a friend threw a brick from an overpass along I-96 in 2003. The brick smashed through a car’s windshield, breaking nearly every bone in the driver’s face.

“It’s affected my life forever and I relive it every day,” Kooiman, 37, said.

In his first interview since it happened, Kooiman shared his story in hopes others can learn from his mistake.

“It only takes one split second to change so many things,” Kooiman said. “And once that happens, you can’t take it back. No matter how much you wish you could.”

Kooiman was 18 at the time. Both he and the friend he was with, Jack Swick, were charged with felony assault.

Kooiman spent a year behind bars and eight years on parole.

FILE – In 2003, Jeff Kooiman and a friend threw a brick from an I-96 overpass. The brick smashed through a car’s windshield, breaking nearly every bone in the driver’s face.

The driver hit by the brick, Vickie Prantle, underwent at least a dozen facial reconstruction surgeries and lost sight in one eye.

Despite her devastating injuries, she never resented the teens for what they’d done.

“It was immediate forgiveness, and it was over with,” Prantle told News 8 during an interview in 2012.

Even with Prantle’s forgiveness, Kooiman has never been able to forgive himself.  

“I am so very thankful that (Prantle) was a Christian woman and it’s opened my eyes to so many things to try and help other people,” Kooiman said.

Kooiman shared his story as a cautionary tale, after learning two young men are on the verge of making the same mistake.

Michigan State Police received multiple reports this week of people throwing pieces of concrete onto US-131 near Byron Center. Several cars were hit, but no one was hurt.

As police search for the suspects, Kooiman’s has this message for them: “Stop now, before someone gets hurt.”

Kooiman wishes he would have thought before he acted.

“I never meant to hurt anybody,” he said. “It was just a prank that went wrong and it’s still hard to move on.”

Prantle’s husband, Bob, told News 8 she’s also upset to learn things are being thrown at moving vehicles. Grounded in her faith, Prantle’s family says she’s moved on with her life and hopes others will do the same.