WASHINGTON - Airbags are supposed to do nothing until you need them. But increasingly, airbags are going off for no apparent reason. Safety devices are harming people. Consider these unexpected threats to your safety:
You are driving along a busy freeway at 100kph, everything normal, when the airbag explodes into your face. Stunned by the impact, enveloped in smoke, disoriented, you throw up your hands.
Arriving home in your driveway, you unbuckle the seat belt and lean forward over the steering wheel to remove the key from the ignition. The airbag explodes into your chest with heart-stopping force.
Just as a friend opens the passenger-side door to get into your minivan, the driver airbag deploys. The force of the detonation throws her to the ground; you are knocked unconscious.
Airbags are not supposed to do any of these things, but they have. Hundreds of complaints about twitchy airbags have been filed with automakers and US regulators since 1993, and more than two million vehicles - about one out of every 38 on the road - have been recalled to repair them.
That ratio will rise to one in 30 if the NHTSA federal agency orders recalls for the vehicles it is now investigating for inadvertent airbag deployment.
Registered complaints about unwanted airbag deployments are increasing at a far faster rate than the growth rate for airbag-equipped vehicles in the total US fleet.
The incidents number in the hundreds. They may have caused one death. The first apparent fatality from an airbag deployment not triggered by a crash is that of Kerri Valecek, a 25-year-old single mother from Streamwood, Illinois.
About one hour after leaving work on 4 February, Valecek was found dead, slumped over the center console of her 1994 Mitsubishi Mirage in a parking lot.
The driver-side-only airbag had deployed, but the car was virtually undamaged.
'There was no reason for that bag to deploy,' contends Kevin Murphy, an attorney for the woman's parents. Murphy theorizes that Valecek suffered a heart-stopping blow to the chest from the airbag.
A coroner's investigation failed to find a cause of death, but forensic pathologist Jeff Harkey observed in a postmortem report that a concussion can kill and yet be undetected in a medical examination. An autopsy disclosed only some minor bruising and hemorrhaging.
Other victims of inadvertent airbag deployments, like 32-year-old Felicia Jones from Chesapeake Beach, Maryland, have lived to tell of their experiences. They say they are left with physical and emotional scars.
'I won't buy an airbag-equipped car again,' said Jones, who now owns a 1987 Plymouth Grand Fury without airbags.
Jones said she was driving her 1995 Chrysler LeBaron convertible along a rural gravel road in southern Maryland last October when the driver bag exploded without cause. The passenger bag did not deploy.
Jones said her right elbow was hyperextended, and tendons were torn by the explosive force. She says she is considering legal action against Chrysler Corp.
George Kirchoff, president of the Automotive Occupant Restraints Council, which represents the airbag industry, does not believe the public is losing confidence in airbags. But he said that 'there should not be any technical obstacle' to improving the already high reliability of airbag
There is, at least for now, support for his position among outside safety groups and important government officials.
'Any sort of safety problem should be an opportunity to improve,' said NHTSA Administrator Ricardo Martinez. 'We should look at it as customer feedback, an opportunity to improve, just like we do in designing cupholders.'
Yet, it is impossible for a manufacturer to turn defects into improvements if engineers cannot determine why airbags are deploying.
Porsche Cars North America is going through just such an experience now.
After a string of 28 reported inadvertent deployments, it has advised owners of 1996 Porsche 911 cars that, if the airbag light on the instrument panel comes on, they should stop driving their cars and have them towed to dealers for service.
Company spokesman Bob Carlson said that if dealers get unclear readouts when they check airbag modules, they will replace the modules and horn relays. But he acknowledged that the source of the problem is not known.
'There is something in that area we haven't isolated yet,' he said.
Safety consultant Ralph Hoar, a regular adviser to plaintiffs' attorneys, blames inadvertent deployments on 'cheap sensors.'
But Hoar is not anti-airbag, and he compared the injuries from inadvertent deployments to the illnesses that occur when vaccines are administered.
'Some of this is to be expected,' he said. 'The reason you don't see more litigation around this is that airbags are preventing more injuries and deaths than they are causing, lots more.'
But Murphy, the Valecek family lawyer, is unhappy about the use of that cost-benefit analysis: 'Airbags are meant to protect, not take lives.'