More than 300 deaths are associated with General Motors recalls, according to a new study by the Center for Auto Safety. (Reuters)

More than 300 deaths are associated with General Motors recalls, according to a new study by the Center for Auto Safety. (Reuters)

Pressure continued to mount on General Motors late Thursday as a review of federal crash data found that 303 drivers and front-seat passengers died in accidents in which air bags did not inflate in two models that the automaker recalled last month.

The review by Friedman Research Corp. was commissioned by the Center for Auto Safety, a consumer group. The center has accused GM and federal auto safety regulators of failing to aggressively pursue complaints about faulty ignition switches that caused cars to stall, disabling their air bags even in violent collisions.

GM announced last month that it was recalling 1.6 million vehicles to repair the defective part, which the automaker said had played a role in 12 deaths. Previously GM said there were 13 deaths.

The review identified fatal accidents recorded in the federal Fatality Analysis Reporting System (FARS) database that involved just two of six models recalled by GM, the 2005-2007 Chevrolet Cobalt and the 2003-2007 Saturn Ion.

The center said that if the other recalled models were evaluated, the death toll would certainly be much higher. Researchers did not attempt to assess whether the faulty switches played a part in the air bags’ failure to deploy.

In a letter to the National Highway Traffic Safety Administration, Clarence Ditlow, executive director of the center, criticized the agency for not doing more to uncover the ignition flaws and demand a recall. He said the NHTSA missed red flags stretching back more than a decade.

“As the agency has done in past investigations, special investigation teams should have been sent out to acquire more information on the crashes found in FARS and determine in which ones the airbag did not deploy due to the ignition key defect.”

The review’s findings were first reported by the New York Times.

The NHTSA has defended its actions, noting that early on it launched three investigations into the accidents. But the agency said those probes were unable to find the exact cause of the accidents amid a blur of complaints and complicating factors, including the introduction of a new type of air bag around the time of the earliest suspicious crashes.

For its part, GM said that the Friedman analysis did not determine why the air bags did not deploy in the fatal accidents.

“As knowledgeable observers know, FARS tracks raw data,” GM spokesman Greg A. Martin said in a statement late Thursday. “Without rigorous analysis, it is pure speculation to attempt to draw any meaningful conclusions. In contrast, research is underway at GM and the investigation of the ignition switch recall and the impact of the defective switch is ongoing.”

The problem with the ignition switches and the amount of time that passed before a recall was ordered have put the NHTSA

and GM in investigators’ crosshairs. Members of both the House and Senate have announced plans to summon GM officials to Capitol Hill for hearings, and a potential criminal investigation is underway at the Justice Department.

View Graphic A history of GM’s ignition problems

Meanwhile, newly installed GM chief executive Mary T. Barra has ordered an internal review that is being led by a former federal prosecutor.

GM has told federal regulators that reports date back as far as 2001, and federal regulators began looking into reports of problematic switches several years later.

But neither party says there was enough evidence to order a recall.

It wasn’t until last month that GM ordered a recall, acting after a rigorous investigation conducted for the company by an outside engineer identified the problem, according to a chronology of events GM has filed with federal regulators.

The recall letters — which the company said went out this week — cover the 2005-07 Chevrolet Cobalt and Pontiac G5, the 2003-07 Saturn Ion, the 2006-07 Chevrolet HHR, the 2006-07 Pontiac Solstice and the 2007 Saturn Sky.