“If there is a canary in the coal mine, it's the rental car companies,” said Maryann Keller, an industry consultant who was a board member at Dollar Thrifty Automotive Group Inc. from 2000 to 2012. “They were the first users of the vehicles en masse.”

Missed Opportunities

The files obtained are among scores exchanged between GM and the U.S. National Highway Traffic Safety Administration over an eight-year period beginning in 2005 related to cars stalling and air bags not deploying in crashes. In the files GM submitted, there were 30 crashes involving 37 fatalities in the Cobalt and the Saturn Ion. The victims' names were redacted.

The documents add to the evidence that GM for at least a decade failed to promptly resolve a wave of complaints from rental-car companies, consumers, automotive reviewers and even its own dealers and mechanics about abnormal crashes that have since been linked to a faulty ignition switch.

The files show many missed opportunities to ask questions and connect disparate events — the very type of evidence that is supposed to be routed to and vetted by the government's Early Warning Reporting system for potential automotive defects.

Follow Up

There's no indication in the files whether GM did or didn't follow through with the vehicle inspection requested by Vanguard in the Barstow, California, incident. GM also told NHTSA that there may not be sufficient information to assign cause to the crash.

Alan Adler, a company spokesman, declined to discuss specific cases for this story. He said the automaker has modified how it handles product defect questions raised by rental-car companies and other fleet customers.

GM ordered recalls early this year for the Cobalt, Ion and four other U.S. models. The automaker has since said that those cars — about 2.6 million of them — may have had faulty ignition switches that when bumped could shut off engines while driving and disable air bags.

By the end of June, the number of cars in North America that GM had called back for repairs related to the ignitions had passed 16 million, more than the 9.71 million vehicles the Detroit-based company sold worldwide in 2013.

Unfamiliar Drivers

The role of rental cars in the GM ignition-switch controversy hasn't been fully examined. Rental cars tend to be driven a lot of miles. They're used by different drivers all the time, many of whom are unfamiliar with the vehicle. That can be the difference in surviving and perishing in an emergency situation, said Clarence Ditlow, executive director of the Washington-based research group Center for Auto Safety.

“The Cobalt was a popular, cheap model for rental-car companies,” Ditlow said. “This highlights why they should be vigilant about handling recalls.”

The flaw in the Cobalt, Ion and four other models has been shown to result in stalling, sudden loss of braking and steering and disabling of the air bags.

Enterprise Crashes

A woman and her ex-husband were killed in a March 2005 crash in Bee Cave, Texas, after she lost control of a Saturn Ion on a rural road. Their teenage daughter, riding in the back seat, suffered serious injuries including brain damage. A police officer on the scene attributed the crash to a braking and steering defect.

The car's owner, Enterprise, noting potential lawsuits, asked GM for an investigation, including an inspection of the car, according to a Saturn customer-assistance center summary.

A July 2005 letter, two months after the initial back-and- forth between Enterprise and GM, shows Enterprise's contractor ELCO telling GM it had the vehicle inspected and didn't find a defect or malfunction.

In a January 2006 crash in Bucks County, Pennsylvania, the police report indicated air bags didn't deploy after a 2006 Cobalt rented from Enterprise slipped off the road and hit a tree, killing the driver.

There was an extended effort to gather information about the crashes, including from the rental companies and the broader consumer fleets. None of the inquiries from NHTSA or the responses from GM gave the agency enough evidence to open a formal defect investigation, a step that could have prompted regulators to order a recall.

The records show that GM's customer service unit referred the case to an investigations unit. There are no records included that show what happened after that.

GM Reorganization

As part of changes implemented following the ignition- switch recall that started in February, a claim that may involve a potential safety issue is now taken to the newly established Emerging Issues team under GM's global safety division, GM's Adler said in an e-mail.

The automaker has reorganized its engineering department in an effort to speed up the handling of potential safety risks and made changes to the legal department in an effort to make sure issues are better communicated than in the past.

NHTSA also has been under scrutiny for missing signs of the broader ignition-switch failures and passing on opening a formal defect investigation in 2007 and again in 2010. The U.S. Transportation Department's inspector general, Calvin Scovel, is reviewing the agency's actions. Transportation Secretary Anthony Foxx said he asked for the review after questions raised by members of Congress, the public and the media.

Senate Hearings

Senator Claire McCaskill, the Missouri Democrat who has presided over two hearings grilling GM Chief Executive Officer Mary Barra, said in July she will hold another hearing to examine the regulator's handling of the recall. Legislation to improve government oversight of the auto industry is expected, she said.

NHTSA's investigation into GM's actions showed the company had evidence of a safety defect that it hid from government investigators, the agency's acting administrator, David Friedman, said in an e-mailed statement.

“GM knew about the safety defect for years, did not report it as required by law and did not take action to protect Americans from that defect until earlier this year,” he said.

Panel Review

“GM's decision-making, structure, process, and corporate culture stood in the way of safety at a time when airbags were failing to work properly in millions of GM products,” he said.

The comments echo what Friedman told Congress in April, when he said the agency would have acted sooner if it had known that GM redesigned its ignition switch in 2006. When an agency panel reviewed information about the Cobalt and Ion in 2007, the cars' failure rates didn't stand out compared with their peers, he said.

The case files obtained by Bloomberg News show exchanges between NHTSA and GM covering 81 crashes. The inquiries were part of the agency's “Early Warning” system, which by its nature sweeps up a lot of disparate information. Not all of the cases are clearly tied to the ignition-switch defect.

NHTSA asked for more information about fatalities that may have involved air-bag failures. Agency investigators never took the next logical step: opening a formal investigation that may have pinpointed a safety defect years before GM itself acted.

At least nine cars owned by rental-car companies are in the crash files as part of investigators' evaluation of air-bag failures.

Pennsylvania Accident

In the 2006 Bucks County incident, an Enterprise claims adjuster asked GM “to set up a claim for a possible defect in the 2006 Chevrolet Cobalt that they rented to a customer,” according to call transcripts from the automaker. “Party of deceased wants vehicle inspected for defects. The air bags did not deploy and the police report states the deceased hit tree for unknown reason.”

The police report indicates the possibility of distraction, driving too fast and over correcting or under correcting on a curve. Roads were wet from rain but the pavement wasn't cold enough to freeze.

“Manufacturer indicates that their investigation did not include an assessment of the alleged defect,” NHTSA's February 9, 2007, summary of the case file says. Agency investigators found two complaints and seven field reports relating to air-bag failures.

'Test Fleet'

Christine Cavallini, a spokeswoman for Enterprise in St. Louis, said the company couldn't locate records related to the crashes that occurred eight and nine years ago. There isn't enough identifying information in the case files redacted by the government, she said.

Cavallini said she isn't aware that Enterprise had any general safety issues involving the Cobalt or Ion.

Attempts to contact lawyers for the victims weren't successful because of the age of the cases and the redacted identification information.

The documents obtained by Bloomberg do show direct correspondence by an Enterprise contractor to GM about the Texas crash, and phone calls between GM and Enterprise about the Pennsylvania incident.

Keller, the former Dollar Thrifty director, said the warnings from the rental car companies should have been a red flag to GM.

“It's really like a test fleet,” she said. “You put a lot of miles on very quick, and any initial defects on the car rise to the surface, and, in fact, that's the way auto companies were supposed to use this. They were supposed to be able to detect defects very early.”

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