Chevy Cobalt - front three-quarter view

Thirteen motorists are dead, and federal safety regulators want to know why.

On Wednesday, the National Highway Traffic Safety Administration announced it would investigate why General Motors delayed a recall of more than 1.37 million vehicles when it knew a defect existed for as long as a decade. In the interim, faulty ignition switches that prevented airbag deployment have been linked to 13 fatalities and caused 31 known crashes.

NHTSA said it would investigate the timeliness of GM's recall, and the Detroit-based automaker could face a financial penalty if investigators find they stalled in fixing a deadly safety issue. Automotive safety advocates say NHTSA could have also investigated sooner.

"NHTSA's enforcement activities have been completely lax, and they let it slide and people died," said Sean Kane, president of Safety Research & Strategies. "And GM's shown a willingness to obfuscate what was really happening."

Alan Batey, General Motors executive

"... the process employed to examine this phenomenon was not as robust as it should have been" - Alan Batey

Documents show that GM was aware of the problem, in which the ignition switches can inadvertently move to the "off" position under pressure from heavy keychains, since 2004. NHTSA had queried the Detroit-based automaker about it as early as 2007.

But GM didn't recall any vehicles because of the problem until last month, when it recalled 619,122 Chevrolet Cobalt and Pontiac G5 models. At that time, the company said it knew of six deaths attributed to the problem. It expanded that campaign earlier this week when it recalled 748,000 more cars, including models of the Saturn Ion, Chevrolet HHR, Pontiac Solstice and Saturn Sky.

In a written statement issued Tuesday, GM president of North America Alan Batey (above) apologized for the belated response.

"The chronology shows that the process employed to examine this phenomenon was not as robust as it should have been," he said. "Today's GM is committed to doing business differently and better. We will take an unflinching look at what happened and apply lessons learned here to improve going forward."

General Motors could face a financial penalty of up to $35 million if NHTSA's investigation reveals it did not recall the vehicles in a timely manner. If the investigation results in the maximum fine, that would be a record. Back in December 2012, Toyota and the US government agreed to a record $17.35M fine for its own recall delays.

Saturn Ion - Red profile

GM is not counting Melton's death as part of its total related to the problem.

It's unclear whether the recalls would have emerged without a court case settled in 2013 between GM and the family of Brooke Melton, a Georgia nurse who was killed in an accident in March 2010 when her 2005 Chevy Cobalt lost power. While working on the case, an attorney who represented the Melton family learned one of GM's engineers had experienced the problem during a test drive in 2004 – before the vehicle was even on sale.

"I think this whole recall comes from that attorney," Kane said. "If it wasn't for his ability to get GM on the record, I don't think this recall happens. Now you have everybody looking at it, and congressmen calling for investigations. ... So this story is far from over, and the longer and harder we look at it, I think we'll have consumers looking at incidents that were not adequately explained before."

The Detroit News reported that GM is not counting Melton's death as part of its total related to the problem.

Industry analysts say they expect the recall news to put a dent, albeit a temporary one, into GM's sales figures.

"Safety is one of the most important attributes a car shopper looks for when considering and purchasing a vehicle," said Tony Lim, senior analyst at Kelley Blue Book. "As GM's current customers and shoppers become aware of the recall, we expect perceptions of safety to be impacted slightly across the lineup."