Ontario’s highest court has sent a warning to garage owners: Lock up your cars or you might be liable for devastating injuries suffered by young car thieves who crash the vehicles.

The Ontario Court of Appeal found that a Bruce County garage is partly liable for a “catastrophic brain injury” a 15-year-old suffered when a car he helped steal from the business crashed in rural Ontario.

Rankin’s Garage & Sales and its owner, James Chad Rankin, were sued for negligence by the teen — known only as JJ. Earlier, a jury had found the business 37% liable and last week the appeals court dismissed Rankin’s appeal.

“Rankin’s garage was an inviting target for theft and joyriding, especially by minors. There was no evidence of any security measures designed to keep people off the property when the business was not open,” Justice Grant Huscroft wrote in a unanimous judgment. “The risk of theft was clear.

“It’s ... common sense that minors might harm themselves in joyriding, especially if they are impaired by alcohol or drugs.”

Huscroft noted that a vehicle was stolen from Rankin’s lot in Paisley years before this incident.

Car theft and mischief were rampant in Paisley, which is 130 kilometres northwest of Kitchener. Local police had a “Lock It or Lose It” program established in 2007 to combat the problem.

JJ was joyriding in a Toyota Camry — driven by his drunken, stoned and unlicensed pal, then 16 — on July 8, 2006, court heard. The Camry was unlocked with its keys inside at Rankin’s lot in Paisley.

The stolen car crashed en route to Walkerton, leaving the 15-year-old with a “catastrophic brain injury,” Huscroft said.

Rankin’s garage had a habit of leaving insecure cars with the keys inside, the judge added.

The appeals court upheld the jury’s ruling that Rankin was 37% liable for damages while the drunk young driver was 23% liable, and his mom — who supplied them with beer — was 30% liable. The passenger was 10% liable for joyriding with an impaired, unlicensed and inexperienced driver.

“It wasn’t onerous for the garage owner to secure his property and he should lock up those cars because of his obligation to the car owners,” winning appeals lawyer Jasmine Akbarali said. “There was a widespread problem of car theft and mischief in that community.”

The amount of the damages paid to the 15-year-old will be determined at a later hearing.

Rankin has 60 days to seek leave to appeal to the Supreme Court.

spazzano@postmedia.com