Viola Stevens had never heard of a power sunroof shattering until hers did as she was driving 100 km/h on a snowy Alberta highway.

“I had no idea what had happened,” Stevens said. “It was extremely loud. I was in shock. I pulled over, (and) promptly started crying and then realized I was in an SUV convertible and it was snowing and minus 22.”

The sunroof glass in her 2013 Kia Sorento shattered with such force she could have lost control and crashed, Stevens said.

The console and the back seat were showered with shards of glass.

“It was extremely scary. If there were any passengers in the back seat they would have definitely been injured, glass in the eye or what-not.”

She had the vehicle towed to the nearest Kia dealer, Sherwood Kia in Sherwood Park, Alta.

Kia Canada replaced the sunroof under warranty at no charge to Stevens.

Later, Stevens found out that her case was just one of many to affect Kia Sorentos and other models.

She said she should have been warned about the possibility before she bought the vehicle.

“It’s something that should be known, should be talked about,” Stevens said. “There should be some sort of statement from Kia.”

Jack Sulymka, Kia spokesman, says the automaker takes customer reports of safety concerns seriously and that in its investigations, it found shattered sunroofs were caused by road debris or hail.

Stevens disputes that, saying there was no other vehicle near her when the glass shattered.

“There was just no reason for it,” she said. “It just exploded.”

Kia is monitoring the performance of the sunroofs and is sharing the results with authorities in Canada and the U.S., Sulymka said.

No recall for Sorento sunroof

Across North America, thousands of vehicles have been recalled for sunroof defects.

Volkswagen has recalled three Audi models, Subaru has recalled 2011 Legacies and Outbacks, and Mitsubishi has recalled 2011 RVRs.

Kia parent Hyundai has recalled 2012 Hyundai Velosters.

But so far, the Kia Sorento hasn’t been recalled, despite an investigation by the U.S. National Highway Transportation Safety Administration of 15 complaints of sunroofs shattering on 2011-2013 models.

Transport Canada said it has received two complaints of sunroof failures on Kia Sorentos and is investigating one case in a “significantly similar” vehicle, the Hyundai Santa Fe.

Likely cause is road debris, AMA says

The Alberta Motor Association agrees with Kia that debris on winter roads is the likely cause of shattering sunroofs.

“Any glass on a vehicle can be compromised once you get a small rock chip,” said Randy Loyk, manager of technical services for the AMA..

Even a small chip becomes a weak spot when the vehicle hits a bump, or a door is slammed during extreme temperature swings, he said.

“In Florida you might not even see this problem, because the roads are dry, they don’t sand them and the roads are nice and smooth.”

Troy Bourassa, VP of operations for AMA Insurance, said AMA has about seven per cent of the Alberta car insurance market and gets four to six sunroof claims a week.

AMA has looked, but hasn’t found any links to a particular manufacturer, which leads them to concludes it isn’t a manufacturer’s defect, he said.

Kia should warn customers, advocate says

The number of Kia Sorento sunroofs being investigated in the U.S. is too great to be the result of random rock chips, said Phil Edmonston, author of the popular Lemon-Aid series of car books.

“I would like to know what is the magnetic attraction Kias have for rocks in their sunroofs,” he said. “It just doesn’t make sense to me.”

Edmonston gives credit to Kia Canada for repairing Stevens’s sunroof under warranty, but says they wouldn’t warranty a windshield for a rock chip so the sunroof repair amounts to an admission there is something wrong with the vehicle.

“You should simply go all the way … and say come on in and we’ll repair it, and it’s got nothing to do with rock chips.”

Kia should warn Sorento buyers that the U.S. government is investigating incidents involving the sunroofs, Edmonston said.

“But that’s wishful thinking,” he said. “Automobile manufacturers don’t want to admit anything and they expect the government to say, ‘These are the investigations we currently have.’”

Different glass may prevent shattering, AMA says.

Both Edmonston and Loyk said whatever the cause of the sunroof glass breaking, the shower of glass Stevens and others experienced is a result of the tempered glass car makers use for sunroofs.

Windshields by comparison, consist of two panes of glass held together with a plastic laminate that holds the glass fragments when the windshield shatters.

Sunroofs are made with a single pane of un-laminated glass.

Loyk said it comes down to money.

“(Manufacturers) could put laminate up top, but it would cost a little bit more. And that’s manufacturers making the decision to keep the cost of the vehicle down,” he said.

It’s significant, Edmonston said, that windshields are peppered with debris every day, but don’t implode into drivers’ faces without warning.

“Windshields are under a regulation that says … they will not shatter and have shards of glass showering the occupants. Well, it’s just as important that sunroofs have the same regulatory protection for consumers.”

Viola Stevens knows the same type of glass has gone back into her repaired Sorento and wonders if it will shatter again.

“I really enjoyed having a sunroof until that happened,” she said. “Now I don’t feel safe in the vehicle anymore.”